IP route command in GRE tunnel
Hello world
I have Setup GRE laboratory between routers R1 and R3.
R1 is connected to R2 using OSPF and R2 is connected to R3 using OSPF.
I have config interface on R1 and R3 GRE tunnel.
R1 has internal subnet say 100.x.x.x.x to share with R3.
R3 has Lan internal subnet say 101.x.x.x.x to share with R1.
Interesting traffic through the GRE tunnel is 100.x.x.x of subnets. and 101.x.x.x.x.
Config of tunnel of R1
R1 # sh run tunnel int 0
Building configuration...
Current configuration: 168 bytes
!
interface Tunnel0
IP 13.13.13.1 255.255.255.0
KeepAlive 3
CDP enable
source of tunnel Loopback0
tunnel destination 20.0.0.1
tunnel path-mtu-discovery
R3 config tunnel
R3 #sh run tunnel int 0
Building configuration...
Current configuration: 158 bytes
!
interface Tunnel0
IP 13.13.13.3 255.255.255.0
KeepAlive 3 1
source of tunnel Loopback0
tunnel destination 10.0.0.1
tunnel path-mtu-discovery
So my question is instead of using routing protocols to advertise the subnets Lan of R1 and R3 can be used for static routes?
for example
If I can use static routes say on R1
IP route 101.101.101.101 255.255.255?
What should be the next jump IP here?
interface of tunnel of the router R3 or physical interface of R3 which connects to R2?
Then the same way I can use static routes on R3 right?
Thank you
Mahesh
Hello Manu,
You can use the IP address as long as addresses IP of the Tunnel on both sides are in the same subnet. So in your case, you can use
!
IP route 101.101.101.101 255.255.255 13.13.13.3
!
Or you can use the interface tunnel
!
IP route 101.101.101.101 255.255.255 Tunnel0
!
Although I saw problems in some cases when the interface name is used instead of IP tunnel.
Please rate this post if helpful.
Thank you
André
Tags: Cisco Security
Similar Questions
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DMVPN GRE tunnel does not connect a failed encapsulate
Hello
I'm trying to set up the tunnel WILL map HWIC Verizon - 3 G-CDMA per Verizons document. Does anyone have a backup on EVDO working?
PDF schema - attached
Verizons - plug
The relevant commands are below
HUB END
interface Tunnel0
IP 192.168.255.89 255.255.255.0
no ip redirection
dynamic multicast of IP PNDH map
PNDH id network IP-100
tunnel source 152.176.219.158
multipoint gre tunnel modeinterface Serial1/0
Verizon MPLS VPN T3 description
IP 152.176.219.158 255.255.255.252
penetration of the IP stream
encapsulation ppp
DSU bandwidth 44210SPOKE ABOUT END
interface Tunnel0
description on the Hub GRE tunnel
IP 192.168.255.29 255.255.255.0
no ip redirection
property intellectual PNDH card 192.168.255.89 152.176.219.158
map of PNDH IP multicast 152.176.219.158
PNDH id network IP-100
property intellectual PNDH nhs 152.176.219.158
registration of the PNDH non-unique IP
source of tunnel Cellular0/1/0
multipoint gre tunnel modethe Cellular0/1/0 interface
Description * VzW EVDO Interface *.
the negotiated IP address
encapsulation ppp
Broadband Dialer
Dialer idle-timeout 0
EVDO Dialer string
Dialer-Group 1
interactive asynchronous mode
PPP chap password 7 120F1F00IP route 152.176.219.158 255.255.255.255 Cellular0/1/0
in the radius of the command... IP PNDH nhs 152.176.219.158 is bad, you need to use the IP tunnel... .IP PNDH nhs 192.168.255.89.
Just in case, here is an example configuration.
http://www.Cisco.com/en/us/Tech/tk583/TK372/technologies_configuration_example09186a008014bcd7.shtml
-
Please see the photo above two connected sites using FA 0/1 R1 and R2 and a GRE Tunnel is formed.
Case 1:
We have a point-to-point connection between two routers and the IP address assigned to FA 0/1 on R1 and R2 belong to the same subnet. We then configure a GRE Tunnel on these as indicated in the topology:
- Using such as eigrp and ospf IGP we can peer routers R1 and R2 using the tunnel and the point-to-point connections.
- This will make the redundant paths between two routers
- This will form the double equal relationship between the two routers (for example for EIGRP or OSPF).
- Or we can tunnel just for the exchange of traffic between two routers.
My Question:
- What is the standard in this topology using the two connection for iGP peering or just tunnel in the real world?
- What is the standard in this topology using the two connection for iGP peering or tunnel just in a review?
Case 2:
If Fa 0/1 on both routers is all public IPs and in fact do not belong to the same subnet. So I think that we have to create a Tunnel between the two routers and then use the tunnel both routers for iGP peer.
My Question:
- I just want to know there is a valid case and also do we get this case in a review?
What comments can you do on both cases freely, I just create these two cases to clear my mind.
Basically the tunnel's link to Point Virtual Point between two routers. When you have two router physically connected by Point to point the link for this tunnel has no utility, but if you have two routers separate my many network jumps then GRE and IPsec tunnel is useful, and in this case tunnel gives you the ease of the logical Point to Point network.
In the tunnel you can run any routing protocol ospf, eigrp, BGP route smiler or Sttic as interface point-to-point between two routers.
Answer to your question on my opinion are as below
case 1
- What is the standard in this topology using the two connection for iGP peering or just tunnel in the real world? -No use of the tunnel in this case in the real world so he will use any routing protocol between physical point-to-point interface.
- What is the standard in this topology using the two connection for iGP peering or tunnel just in a review? -Same as above point Exam are mostly due to the scenario of the real world (not sure what you're talking about what exam).
Case 2
- I just want to know there is a valid case and also do we get this case in a review? -Yes, this is valid in the real world, but also optical examination specially DMVPN and Ipsec tunnel in the CCIE exam.
Please always evaluate the useful post!
Kind regards
Pawan (CCIE # 52104)
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Questions about the Internet browsing GRE tunnel ISPec
I am faced with Internet navigation problems when distened to the customer's internet traffic. mail.Yahoo.com does not open on the client, while yahoo.com works very well. Same streaming and apps from apple works does not on iphone, but distened for data center traffic works very well. If I remove the protection of IPSec of GRE tunnel then everything works fine.
Please guide what to do, I have attached a diagram of scenario
Hello
It is difficult to suggest, but MTU issue could be the reason for the problem.
Do you have the command of setting-mss tcp ip on both interfaces of tunnel?
If not, please try to add:
Tunnel X interface
IP tcp adjust-mss 1300
If it helps, you can try to increase the value of 1300 to 1360 MMS (which is recommended by Cisco)
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I have a router Cisco 2811 configured with a GRE tunnel, and I want to add another tunnel to another remote site. It's the first tunnel configuration:
Tunnel1 interface
IP 10.1.1.1 255.255.255.252
IP access-group 10 out
IP nat inside
IP virtual-reassembly
KeepAlive 10 3
source of tunnel Vlan1
tunnel destination xxx.xxx.xxx.xxx
card crypto IPSEC_VPN
I have some doubts on that subnet to configure for the second tunnel.
In the existing tunnel, the IP address is: 10.1.1.1 and mask: 255.255.255.252 subnet so is 10.1.1.0. I guess, I have to configure another different subnet (i.e. 10.1.2.0) for the second tunnel, but what IP address and the mask, 10.1.2.1 255.255.255.0?
When a PC from the router's local network tries to connect to the remote router using the tunnel, what IP address it use?
Thanks and greetings
You're wrong, your PC's need is a route of default gateway for the router, a default route is a route that defines, all unknown IP traffic must be forwarded to the next hop that is defined in the default route.
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GRE tunnels will not come on VPN IPsec/GRE
Hi all
We have 400 + remote sites that connect to our central location (and a backup site) using Cisco routers with vpn IPSec/GRE tunnels. We use a basic model for the creation of tunnels, so there is very little chance of a bad configuration on each router. Remote sites use Cisco 831 s, central sites use Cisco 2821 s. There is a site where the tunnels WILL refuse just to come.
Routers are able to ping their public IP addresses, so it is not a routing problem, but gre endpoints cannot ping. There is no NATing involved, two routers directly accessing the Internet. The assorded display orders seem to indicate that the SAs are properly built, but newspapers, it seems that last part just don't is finished, and the GRE tunnels come not only upward.
The attached log file, it seems that both its IPSEC & ISAKMP are created @ 00:25:14, then QM_PHASE2 end @ 00:25:15.
00:25:15: ISAKMP: (0:10:HW:2): node error 1891573546 FALSE reason for deletion "(wait) QM.
00:25:15: ISAKMP: (0:10:HW:2): entrance, node 1891573546 = IKE_MESG_FROM_PEER, IKE_QM_EXCH
00:25:15: ISAKMP: (0:10:HW:2): former State = new State IKE_QM_R_QM2 = IKE_QM_PHASE2_COMPLETE
00:25:15: ISAKMP (0:268435467): received 208.XX packet. Dport 500 sport Global 500 (I) QM_IDLE yy.11
00:25:15: IPSEC (key_engine): had an event of the queue with 1 kei messages
00:25:15: IPSEC (key_engine_enable_outbound): rec would prevent ISAKMP
00:25:15: IPSEC (key_engine_enable_outbound): select SA with spinnaker 1572231461/50
00:25:15: ISAKMP: (0:11:HW:2): error in node-1931380074 FALSE reason for deletion "(wait) QM.
00:25:15: ISAKMP: (0:11:HW:2): entrance, node-1931380074 = IKE_MESG_FROM_PEER, IKE_QM_EXCH
00:25:15: ISAKMP: (0:11:HW:2): former State = new State IKE_QM_R_QM2 = IKE_QM_PHASE2_COMPLETE
00:25:15: IPSEC (key_engine): had an event of the queue with 1 kei messages
00:25:15: IPSEC (key_engine_enable_outbound): rec would prevent ISAKMP
00:25:15: IPSEC (key_engine_enable_outbound): select SA with spinnaker 310818168/50I don't have the remote router log file, and is very long, so I joined her. Before that I captured the log file, I enabled debugging ipsec & isakmp and immediately authorized the SAs.
Assorted useful details and matching orders of show results:
Cisco IOS Software, C831 (C831-K9O3SY6-M), Version 12.4 (25), RELEASE SOFTWARE (fc1)
There are 2 connections of IPSEC/GRE tunnel:
Tunnel101: KC (208.YY. ZZ.11) - remote control (74.WW. XX.35)
Tunnel201: Dallas (208.XX. YY.11) - remote control (74.WW. XX.35)Site-382-831 #sho ip int br
Interface IP-Address OK? Method State Protocol
FastEthernet1 unassigned YES unset down down
FastEthernet2 unassigned YES unset upward, upward
FastEthernet3 unassigned YES unset upward, upward
FastEthernet4 unassigned YES unset upward, upward
Ethernet0 10.3.82.10 YES NVRAM up up
Ethernet1 74.WW. XX.35 YES NVRAM up up
Ethernet2 172.16.1.10 YES NVRAM up up
Tunnel101 1.3.82.46 YES NVRAM up toward the bottom<>
Tunnel201 1.3.82.62 YES NVRAM up toward the bottom<==== ="">====>
NVI0 unassigned don't unset upward upwardsSite-382-831 #.
Site-382-831 #sho run int tunnel101
Building configuration...Current configuration: 277 bytes
!
interface Tunnel101
Description % connected to the 2nd KC BGP 2821 - PRI - B
IP 1.3.82.46 255.255.255.252
IP mtu 1500
IP virtual-reassembly
IP tcp adjust-mss 1360
KeepAlive 3 3
source of tunnel Ethernet1
destination of the 208.YY tunnel. ZZ.11
endSite-382-831 #.
Site-382-831 #show isakmp crypto his
status of DST CBC State conn-id slot
208.XX. YY.11 74.WW. XX.35 QM_IDLE ASSETS 0 11
208.YY. ZZ.11 74.WW. XX.35 QM_IDLE 10 0 ACTIVE
Site-382-831 #.Site-382-831 #.
Site-382-831 #show detail of the crypto isakmp
Code: C - IKE configuration mode, D - Dead Peer Detection
NAT-traversal - KeepAlive, N - K
X - IKE extended authentication
PSK - GIPR pre-shared key - RSA signature
renc - RSA encryptionC - id Local Remote I have VRF status BA hash Auth DH lifetime limit.
11 74.WW. XX.35 208.XX. YY.11 ACTIVE 3des sha psk 1 23:56:09
Connection-id: motor-id = 11:2 (hardware)
74.WW 10. XX.35 208.YY. ZZ.11 ACTIVE 3des sha psk 1 23:56:09
Connection-id: motor-id = 10:2 (hardware)
Site-382-831 #.Site-382-831 #.
Site-382-831 #show crypto ipsec hisInterface: Ethernet1
Tag crypto map: IPVPN_MAP, local addr 74.WW. XX.35protégé of the vrf: (none)
ident (addr, mask, prot, port) local: (74.WW. XX.35/255.255.255.255/47/0)
Remote ident (addr, mask, prot, port): (208.YY. ZZ.11/255.255.255.255/47/0)
current_peer 208.YY. ZZ.11 port 500
LICENCE, flags is {origin_is_acl},
#pkts program: 2333, #pkts encrypt: 2333, #pkts digest: 2333
#pkts decaps: 0, #pkts decrypt: 0, #pkts check: 0
compressed #pkts: 0, unzipped #pkts: 0
#pkts uncompressed: 0, #pkts compr. has failed: 0
#pkts not unpacked: 0, #pkts decompress failed: 0
#send 21, #recv errors 0local crypto endpt. : 74.WW. XX.35, remote Start crypto. : 208.YY. ZZ.11
Path mtu 1500, mtu 1500 ip, ip mtu IDB Ethernet1
current outbound SPI: 0x45047D1D (1157922077)SAS of the esp on arrival:
SPI: 0x15B97AEA (364477162)
transform: esp-3des esp-sha-hmac.
running parameters = {Tunnel}
Conn ID: 2004, flow_id: C83X_MBRD:4, crypto card: IPVPN_MAP
calendar of his: service life remaining (k/s) key: (4486831/1056)
Size IV: 8 bytes
support for replay detection: Y
Status: ACTIVEthe arrival ah sas:
SAS of the CFP on arrival:
outgoing esp sas:
SPI: 0x45047D1D (1157922077)
transform: esp-3des esp-sha-hmac.
running parameters = {Tunnel}
Conn ID: 2003, flow_id: C83X_MBRD:3, crypto card: IPVPN_MAP
calendar of his: service life remaining (k/s) key: (4486744/1056)
Size IV: 8 bytes
support for replay detection: Y
Status: ACTIVEoutgoing ah sas:
outgoing CFP sas:
protégé of the vrf: (none)
ident (addr, mask, prot, port) local: (74.WW. XX.35/255.255.255.255/47/0)
Remote ident (addr, mask, prot, port): (208.XX. YY.11/255.255.255.255/47/0)
current_peer 208.XX. YY.11 port 500
LICENCE, flags is {origin_is_acl},
#pkts program: 2333, #pkts encrypt: 2333, #pkts digest: 2333
#pkts decaps: 0, #pkts decrypt: 0, #pkts check: 0
compressed #pkts: 0, unzipped #pkts: 0
#pkts uncompressed: 0, #pkts compr. has failed: 0
#pkts not unpacked: 0, #pkts decompress failed: 0
#send 21, #recv errors 0local crypto endpt. : 74.WW. XX.35, remote Start crypto. : 208.XX. YY.11
Path mtu 1500, mtu 1500 ip, ip mtu IDB Ethernet1
current outbound SPI: 0xE82A86BC (3895101116)SAS of the esp on arrival:
SPI: 0x539697CA (1402378186)
transform: esp-3des esp-sha-hmac.
running parameters = {Tunnel}
Conn ID: 2008, flow_id: C83X_MBRD:8, crypto card: IPVPN_MAP
calendar of his: service life remaining (k/s) key: (4432595/1039)
Size IV: 8 bytes
support for replay detection: Y
Status: ACTIVEthe arrival ah sas:
SAS of the CFP on arrival:
outgoing esp sas:
SPI: 0xE82A86BC (3895101116)
transform: esp-3des esp-sha-hmac.
running parameters = {Tunnel}
Conn ID: 2001, flow_id: C83X_MBRD:1, crypto card: IPVPN_MAP
calendar of his: service life remaining (k/s) key: (4432508/1039)
Size IV: 8 bytes
support for replay detection: Y
Status: ACTIVEoutgoing ah sas:
outgoing CFP sas:
Site-382-831 #.Site-382-831 #.
Site-382-831 #show crypto ipsec his | Pkts Inc. | life
#pkts program: 2397, #pkts encrypt: 2397, #pkts digest: 2397
#pkts decaps: 0, #pkts decrypt: 0, #pkts check: 0
compressed #pkts: 0, unzipped #pkts: 0
#pkts uncompressed: 0, #pkts compr. has failed: 0
#pkts not unpacked: 0, #pkts decompress failed: 0
calendar of his: service life remaining (k/s) key: (4486831/862)
calendar of his: service life remaining (k/s) key: (4486738/862)
#pkts program: 2397, #pkts encrypt: 2397, #pkts digest: 2397
#pkts decaps: 0, #pkts decrypt: 0, #pkts check: 0
compressed #pkts: 0, unzipped #pkts: 0
#pkts uncompressed: 0, #pkts compr. has failed: 0
#pkts not unpacked: 0, #pkts decompress failed: 0
calendar of his: service life remaining (k/s) key: (4432595/846)
calendar of his: service life remaining (k/s) key: (4432501/846)
Site-382-831 #.Site-382-831 #.
Site-382-831 #show crypto isakmp policyWorld IKE policy
Priority protection Suite 10
encryption algorithm: three key triple a
hash algorithm: Secure Hash Standard
authentication method: pre-shared Key
Diffie-Hellman group: #1 (768 bits)
lifetime: 86400 seconds, no volume limit
Default protection suite
encryption algorithm: - Data Encryption STANDARD (56-bit keys).
hash algorithm: Secure Hash Standard
authentication method: Rivest-Shamir-Adleman Signature
Diffie-Hellman group: #1 (768 bits)
lifetime: 86400 seconds, no volume limit
Site-382-831 #.Site-382-831 #show crypto card
"IPVPN_MAP" 101-isakmp ipsec crypto map
Description: at the 2nd KC BGP 2821 - PRI - B
Peer = 208.YY. ZZ.11
Extend the PRI - B IP access list
access list PRI - B allowed will host 74.WW. XX.35 the host 208.YY. ZZ.11
Current counterpart: 208.YY. ZZ.11
Life safety association: 4608000 Kbytes / 3600 seconds
PFS (Y/N): N
Transform sets = {}
IPVPN,
}"IPVPN_MAP" 201-isakmp ipsec crypto map
Description: 2nd Dallas BGP 2821 - s-B
Peer = 208.XX. YY.11
Expand the list of IP SEC-B access
s - B allowed will host 74.WW access list. XX.35 the host 208.XX. YY.11
Current counterpart: 208.XX. YY.11
Life safety association: 4608000 Kbytes / 3600 seconds
PFS (Y/N): N
Transform sets = {}
IPVPN,
}
Interfaces using crypto card IPVPN_MAP:
Ethernet1
Site-382-831 #.Tunnel between KC & the remote site configuration is:
Distance c831 - KC
crypto ISAKMP policy 10
BA 3des
preshared authentication
!
PRI-B-382 address 208.YY isakmp encryption key. ZZ.11
!
Crypto ipsec transform-set esp-3des esp-sha-hmac IPVPN
transport mode
!
IPVPN_MAP 101 ipsec-isakmp crypto map
Description of 2nd KC BGP 2821 - PRI - B
set of peer 208.YY. ZZ.11
game of transformation-IPVPN
match address PRI - B
!
interface Tunnel101
Description % connected to the 2nd KC BGP 2821 - PRI - B
IP 1.3.82.46 255.255.255.252
IP mtu 1500
KeepAlive 3 3
IP virtual-reassembly
IP tcp adjust-mss 1360
source of tunnel Ethernet1
destination of the 208.YY tunnel. ZZ.11
!
interface Ethernet0
private network Description
IP 10.3.82.10 255.255.255.0
IP mtu 1500
no downtime
!
interface Ethernet1
IP 74.WW. XX.35 255.255.255.248
IP mtu 1500
automatic duplex
IP virtual-reassembly
card crypto IPVPN_MAP
no downtime
!
PRI - B extended IP access list
allow accord 74.WW the host. XX.35 the host 208.YY. ZZ.11
!KC-2821 *.
PRI-B-382 address 74.WW isakmp encryption key. XX.35
!
PRI-B-382 extended IP access list
allow accord 208.YY the host. ZZ.11 the host 74.WW. XX.35
!
IPVPN_MAP 382 ipsec-isakmp crypto map
Description % connected to the 2nd KC BGP 2821
set of peer 74.WW. XX.35
game of transformation-IPVPN
match address PRI-B-382
!
interface Tunnel382
Description %.
IP 1.3.82.45 255.255.255.252
KeepAlive 3 3
IP virtual-reassembly
IP tcp adjust-mss 1360
IP 1400 MTU
delay of 40000
tunnel of 208.YY origin. ZZ.11
destination of the 74.WW tunnel. XX.35
!
endAny help would be much appreciated!
Mark
Hello
logs on Site-382-831, only see the crypt but none decrypts, could you check a corresponding entry on the peer and see if has any questions send return traffic?
Site-382-831 #show crypto ipsec his | Pkts Inc. | life
#pkts program: 2397, #pkts encrypt: 2397, #pkts digest: 2397
#pkts decaps: 0, #pkts decrypt: 0, #pkts check: 0
compressed #pkts: 0, unzipped #pkts: 0
#pkts uncompressed: 0, #pkts compr. has failed: 0
#pkts not unpacked: 0, #pkts decompress failed: 0
calendar of his: service life remaining (k/s) key: (4486831/862)
calendar of his: service life remaining (k/s) key: (4486738/862)
#pkts program: 2397, #pkts encrypt: 2397, #pkts digest: 2397
#pkts decaps: 0, #pkts decrypt: 0, #pkts check: 0
compressed #pkts: 0, unzipped #pkts: 0
#pkts uncompressed: 0, #pkts compr. has failed: 0
#pkts not unpacked: 0, #pkts decompress failed: 0
calendar of his: service life remaining (k/s) key: (4432595/846)
calendar of his: service life remaining (k/s) key: (4432501/846)
Site-382-831 #.Kind regards
Averroès.
-
Configuration of Site VPN connection to another via GRE Tunnels
I am trying to connect VPN site to site on the internet using GRE tunnels. I am able to reach from a WAN interface to another. But I am not able to get the ISAKMP and IPSec to work. Below the configuration and a simplified below flowchart. In the scenario below, I am also running BGP between these routers. The BGP neighbor-ships are trained through the tunnels. But I want traffic between tunnels to encrypt. IPsec and ISAKMP not running BGP routes and other traffic is not encrypted.
This is why I would like to know what could the reason for this.
Router config VPN 1
crypto isakmp policy 1 encr 3des authentication pre-share group 2 lifetime 500 crypto isakmp key test_key1 address 192.168.30.1 crypto isakmp key test_key1 address 192.168.30.2 crypto isakmp keepalive 60 20 crypto isakmp aggressive-mode disable ! ! crypto ipsec transform-set high esp-3des esp-sha-hmac mode tunnel ! ! ! crypto map CRYP_MAP_IPSEC 10 ipsec-isakmp set peer 192.168.20.1 set security-association lifetime seconds 4000 set transform-set high set pfs group2 match address 110 crypto map CRYP_MAP_IPSEC 20 ipsec-isakmp set peer 192.168.20.2 set security-association lifetime seconds 4000 set transform-set high set pfs group2 match address 111 ! interface Loopback0 description IPsec_Tunnel0 ip address 192.168.30.1 255.255.255.255 ! interface Loopback1 description IPsec_Tunnel1 ip address 192.168.30.2 255.255.255.255 ! interface Loopback2 description BGP_Peer1 ip address 192.168.40.1 255.255.255.255 ! interface Loopback3 description BGP_Peer2 ip address 192.168.40.2 255.255.255.255 ! interface Tunnel0 ip unnumbered Loopback0 tunnel source Loopback0 tunnel destination 192.168.20.1 crypto map CRYP_MAP_IPSEC ! interface Tunnel1 ip unnumbered Loopback1 tunnel source Loopback1 tunnel destination 192.168.20.2 crypto map CRYP_MAP_IPSEC ! interface gi0 description #### CONNECTED TO Internet #### ip address 10.1.1.1 255.255.255.252 ip access-group 100 in duplex auto speed auto ! router bgp 64851 bgp log-neighbor-changes neighbor BGP_PEER_1 peer-group neighbor BGP_PEER_1 remote-as 64859 neighbor BGP_PEER_1 ebgp-multihop 255 neighbor BGP_PEER_1 update-source Loopback2 neighbor BGP_PEER_1 version 4 neighbor BGP_PEER_1 next-hop-self neighbor BGP_PEER_2 peer-group neighbor BGP_PEER_2 remote-as 64859 neighbor BGP_PEER_2 ebgp-multihop 255 neighbor BGP_PEER_2 update-source Loopback3 neighbor BGP_PEER_2 version 4 neighbor BGP_PEER_2 next-hop-self neighbor 192.168.10.1 peer-group BGP_PEER_1 neighbor 192.168.10.2 peer-group BGP_PEER_2 ! ip route 192.168.10.1 255.255.255.255 Tunnel0 ip route 192.168.10.2 255.255.255.255 Tunnel1 ip route 192.168.20.1 255.255.255.255 GigabitEthernet0 ip route 192.168.20.2 255.255.255.255 GigabitEthernet0 ! access-list 100 permit ip any any access-list 110 permit gre host 192.168.30.1 host 192.168.20.1 access-list 110 permit gre host 192.168.20.1 host 192.168.30.1 access-list 111 permit gre host 192.168.30.2 host 192.168.20.2 access-list 111 permit gre host 192.168.20.2 host 192.168.30.2 ======================================================================
Router config VPN 2
crypto isakmp policy 1 encr 3des authentication pre-share group 2 lifetime 500 crypto isakmp key test_key1 address 192.168.30.1 crypto isakmp key test_key1 address 192.168.30.2 crypto isakmp keepalive 60 20 crypto isakmp aggressive-mode disable ! ! crypto ipsec transform-set high esp-3des esp-sha-hmac mode tunnel ! ! ! crypto map CRYP_MAP_IPSEC 10 ipsec-isakmp set peer 192.168.30.1 set security-association lifetime seconds 4000 set transform-set high set pfs group2 match address 110 crypto map CRYP_MAP_IPSEC 20 ipsec-isakmp set peer 192.168.30.2 set security-association lifetime seconds 4000 set transform-set high set pfs group2 match address 111 ! interface Loopback0 description IPsec_Tunnel0 ip address 192.168.20.1 255.255.255.255 ! interface Loopback1 description IPsec_Tunnel1 ip address 192.168.20.2 255.255.255.255 ! interface Loopback2 description BGP_Peer1 ip address 192.168.10.1 255.255.255.255 ! interface Loopback3 description BGP_Peer2 ip address 192.168.10.2 255.255.255.255 ! interface Tunnel0 ip unnumbered Loopback0 tunnel source Loopback0 tunnel destination 192.168.30.1 crypto map CRYP_MAP_IPSEC ! interface Tunnel1 ip unnumbered Loopback1 tunnel source Loopback1 tunnel destination 192.168.30.2 crypto map CRYP_MAP_IPSEC ! interface gi0 description #### CONNECTED TO Internet #### ip address 10.1.1.2 255.255.255.252 ip access-group 100 in duplex auto speed auto ! router bgp 64859 bgp log-neighbor-changes neighbor BGP_PEER_1 peer-group neighbor BGP_PEER_1 remote-as 64851 neighbor BGP_PEER_1 ebgp-multihop 255 neighbor BGP_PEER_1 update-source Loopback2 neighbor BGP_PEER_1 version 4 neighbor BGP_PEER_1 next-hop-self neighbor BGP_PEER_2 peer-group neighbor BGP_PEER_2 remote-as 64851 neighbor BGP_PEER_2 ebgp-multihop 255 neighbor BGP_PEER_2 update-source Loopback3 neighbor BGP_PEER_2 version 4 neighbor BGP_PEER_2 next-hop-self neighbor 192.168.40.1 peer-group BGP_PEER_1 neighbor 192.168.40.2 peer-group BGP_PEER_2 ! ip route 192.168.40.1 255.255.255.255 Tunnel0 ip route 192.168.40.2 255.255.255.255 Tunnel1 ip route 192.168.30.1 255.255.255.255 gi0 ip route 192.168.30.2 255.255.255.255 gi0 ! access-list 100 permit ip any any access-list 110 permit gre host 192.168.20.1 host 192.168.30.1 access-list 110 permit gre host 192.168.30.1 host 192.168.20.1 access-list 111 permit gre host 192.168.20.2 host 192.168.30.2 access-list 111 permit gre host 192.168.30.2 host 192.168.20.2 ======================================================================
Encryption of your Tunnel configuration is incorrect... you need to do something about the following at both ends.
crypto ISAKMP policy 10 aes encryption sha hash preshared authentication Group 5 cisco crypto isakmp key address Crypto ipsec transform-set esp - aes 256 esp-sha-hmac RIGHT Profile of crypto ipsec MYPROFILE transformation-RIGHT game interface tunnel 10 Unnumbered IP gig0/0 tunnel source gig0/0 tunnel destination ipv4 ipsec tunnel mode Profile of tunnel MYPROFILE ipsec protection --
Please do not forget to select a correct answer and rate useful posts
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Package and drop on GRE tunnel CPU high usage
Hello world
We have GRE tunnel between 2 sites.
Users have complained about the slow pace and I checked the CPU usage is too high.
She went from 40-70% on average in the last hours.
Here is the setting of the tunnel interface
MTU 17916 bytes, BW 100 Kbit, DLY 50000 usec,
reliability 255/255, txload 235/255, rxload 241/255
Input queue: 0, 75, 4339, 0 (size/max/drops/dumps); Total output drops: 89
Other end has 39 drops
Is it ok to have drops when there is large amount of traffic through the tunnel of?.
Need to know what I should look for?
Are these drops 89 ok to have?
Thank you
MAhesh
Hello Manu,
If this is not yet a subject that would be close to me, but I'll have a try.
What model device you use on the site where you use an observer the CPU high? Maybe the device cannot handle the amount of traffic using this method?
Can you post any output of the command "show interface Tunnel x"?
What type of connection WAN this GRE Tunnel use?
Is the bandwidth on what whether failure 8000 kbps both inside and outside?
I think that you can configure by using the commands
"transmission of bandwidth of tunnel.
"bandwidth tunnel receive."
There also a command
"bandwidth".
What you use this connection for, were there changes in the use of network between sites that would explain the increased use of the processor?
It seems according to the output above the Tunnel is simply "push and in" as much traffic as possible. Or as much traffic it can push accoring to the configuration of the interface.
txload 235/255, rxload 241/255
This coupled with high CPU usage could explain naturally drops. Although of course, the CPU usage is probably the effect of the use of the tunnel bandwidth.
-Jouni
-
I am doing a test vpn on a router to an ASA 18xx.
the existing router already has 3 site-to-site vpn/s. They use GRE tunnels. I would like to add another site to site VPN but not not using gre Tunnels.
I don't have what an output interface, which has the card crypto applied gre. If I add it to the existing encryption card, he will try to go through the gre tunnel
Is there a way I can get this to work?
This part of the config seems to be OK.
You need to know why the tunnel peer X.X.X.44 is not to build.
Check the ACL 180 and also make sure that you are not blocking that traffic to AL-FA0-IN
I see you do NAT on fa0 - propably you have to exclude that VPN NAT traffic.
---
Michal
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Using Gre Tunnel between devices on the same LAN
Hello world
When we need to use the Gre Tunnel on same side means on 2 devices to each other on the LAN?
Whats is advantage of using GRe Tunnel on LAN?
Thank you
MAhesh
In general, GRE tunnel is not on the same side/network.
It serves to connect 2 networks and to get through the traffic.
GRE advantage is that it can participate in routing protocols, then it becomes a little jump through the tunnel instead of several jumps across different devices. As a result, the GRE is also used for tunnel traffic that is not natively supported by these devices where the type not supported traffic cannot pass through.
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Hello, I have a radio link with a branch, but the link to the provider is not approved to set up a Tunnel GRE + IPSec, but I get that this log in my router.
% CRYPTO-4-PKT_REPLAY_ERR: decrypt: re-read the verification failed
The topology is:
Router 1 C3825 IOS 12.4 (25f) Fa0/2/2 - link radio - router 2 C3825 IOS 15.1 (4) M4 Gi0/1
I get the logs into the Router 1 only.
Configurations are:
Router 1:
crypto ISAKMP policy 1
BA aes
md5 hash
preshared authentication
Group 2
ISAKMP crypto key Andina12 address 172.20.127.114
invalid-spi-recovery crypto ISAKMP
!
!
Crypto ipsec transform-set TS aes - esp esp-md5-hmac
!
Profile of crypto ipsec protected-gre
86400 seconds, life of security association set
game of transformation-TS
interface Tunnel0
Description IPSec Tunnel of GRE a Víbora
bandwidth 2000
IP 172.20.127.117 255.255.255.252
IP 1400 MTU
IP tcp adjust-mss 1360
tunnel source 172.20.127.113
tunnel destination 172.20.127.114
protection ipsec profile protected-gre tunnel
interface FastEthernet0/2/2
Description RadioEnlace a Víbora
switchport access vlan 74
bandwidth 2000
No cdp enable
interface Vlan74
bandwidth 2000
IP 172.20.127.113 255.255.255.252
Router eigrp 1
network 172.20.127.116 0.0.0.3
Router 2:
crypto ISAKMP policy 1
BA aes
md5 hash
preshared authentication
Group 2
ISAKMP crypto key Andina12 address 172.20.127.113
!
!
Crypto ipsec transform-set TS aes - esp esp-md5-hmac
!
Profile of crypto ipsec protected-gre
86400 seconds, life of security association set
game of transformation-TS
interface Tunnel0
Description IPSec Tunnel of GRE a CSZ
bandwidth 2000
IP 172.20.127.118 255.255.255.252
IP 1400 MTU
IP tcp adjust-mss 1360
tunnel source 172.20.127.114
tunnel destination 172.20.127.113
protection ipsec profile protected-gre tunnel
interface GigabitEthernet0/1
Description Radio Enlace a CSZ
bandwidth 2000
IP 172.20.127.114 255.255.255.252
automatic duplex
automatic speed
media type rj45
No cdp enable
Router eigrp 1
network 172.20.127.116 0.0.0.3
Thanks for the help.
Yes, you can have just as configured:
Crypto ipsec transform-set esp - aes TS
transport mode
Be sure to change it on both routers.
-
The GRE Tunnel descends?
So here's my setup:
Internal router (2821) > Cluster internal DMZ ASA > router DMZ (2821) > external DMZ Checkpoint Cluster > Branch Office router (877)
Internal Cluster ASA a configured PAT production internal then all the VLANS.
The router in the DMZ has an interior interface configured on the internal DMZ and an external interface configured on the external DMZ. The DMZ router has two interfaces configured loopback.
The external control point is configured with NAT for the incoming and outgoing traffic.
The branch is a DSL router with a static IP address.
The first requirement is to configure a GRE IPSec tunnel between the DMZ router and the branch office router.
The second condition is to configure a GRE IPSec tunnel between the internal router and the router in the DMZ.
The third requirement is to allow routing between the internal router and the branch through the router in the DMZ, because it is ultimately the connection between the head office and branch of live backup.
I configured a Contract by the IPSec Tunnel between the router in the DMZ and routers of Management Office successfully.
I can also set up a GRE Tunnel (without IPSec) between the internal router and the router in the DMZ.
However, whenever the GRE Tunnel establishes between internal and DMZ routers and a neighbouring forms EIGRP, EIGRP neighborhood between the router in the DMZ and the branch drops! See following the DMZ router log file:
1 = to branch tunnel
Tunnel of 100 = internal
002885:. 3 Mar 22:32:57.013: % LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel1, changed State to
002886:. 3 Mar 22:33:06.029: % DUAL-5-NBRCHANGE: IPv4 EIGRP 1: neighbor 172.17.205.61 (Tunnel1) is on the rise: new adjacency
002889:. 3 Mar 22:33:58.434: % LINK-3-UPDOWN: Interface Tunnel100, changed State to
002890.: 3 Mar 22:33:58.438: % LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel100, changed State to
002891:. 3 Mar 22:34:15.370: % DUAL-5-NBRCHANGE: IPv4 EIGRP 1: neighbor 192.168.5.66 (Tunnel100) is on the rise: new adjacency
002892:. 22:34:30.551 3 Mar: % DUAL-5-NBRCHANGE: 1 IPv4 EIGRP: neighbour 172.17.205.61 (Tunnel1) is falling: expiry of hold time
002893:. 3 Mar 22:34:47.015: % LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel1, state change downstairsThe IPSec tunnel, for the branch remains in place throughout.
Can anyone help!?
The problem was that whenever the GRE Tunnel established between internal and DMZ routers and a forms of EIGRP neighbor branch was learning the next hop to the destination of tunnel from a different device.
This is how the branch was to learn the route to the tunnel destination:
Tunnel1 interface
Tandragee Sub Station router VPN Tunnel description
bandwidth 64
IP 172.17.205.62 255.255.255.252
no ip-cache cef route
delay of 20000
KeepAlive 10 3
source of tunnel Loopback1
tunnel destination 172.17.255.23
be-idz-vpn-01 #sh ip route 172.17.255.23
Routing for 172.17.255.23/32 entry
Through the 'static', the metric distance 1 0 known
Routing descriptor blocks:
* 172.17.252.129
Path metric is 0, number of shares of traffic 1
be-idz-vpn-01 #sh ip route 172.17.252.129
Routing for 172.17.252.128/25 entry
Known via 'connected', distance 0, metric 0 (connected, via the interface)
Routing descriptor blocks:
* directly connected by GigabitEthernet0/1
Path metric is 0, number of shares of traffic 1
be-idz-vpn-01 #.
This is how the next hop as learned GRE Tunnel between internal and DMZ routers
be-idz-vpn-01 #sh ip route 172.17.252.129
Routing for 172.17.252.128/27 entry
By the intermediary of "eigrp 1", the known distance 170, metric 40258816, type external
Redistribution via eigrp 1
Last updated on Tunnel100 192.168.5.66, ago 00:07:25
Routing descriptor blocks:
* 192.168.5.66, 192.168.5.66, there is, through Tunnel100 00:07:25
Path metric is 40258816, 1/number of shares of traffic is
Time total is 10110 microseconds, minimum bandwidth 64 Kbps
Reliability 255/255, MTU minimum 1476 bytes
Loading 1/255, 2 hops
We can see how the next hop to the destination of tunnel 172.17.255.23 changed from known via 'connected' via GigabitEthernet0/1 known via "eigrp 1" through Tunnel100.
This case causes the Tunnel 1 drops.
The reason for this behavior was because the road to reach the next hop was acquired with a longest match through tunnel interface so that he won the race to the routing table.
The solution we applied:
Created a list of distribution on the branch office router in order to remove this specific route Tunnel 100 updates.
Router eigrp 1
distribute-list 1
Network 10.10.10.0 0.0.0.3
network 172.17.203.56 0.0.0.3
network 172.17.203.60 0.0.0.3
network 172.17.205.60 0.0.0.3
network 172.19.98.18 0.0.0.0
network 192.168.5.64 0.0.0.3
passive-interface Loopback1
be-idz-vpn-01 #sh access-list 1
IP access list standard 1
10 deny 172.17.252.128, wildcard bits 0.0.0.127 (1 match)
20 permit (1230 matches)
be-idz-vpn-01 #.
Once this has been applied, we could have the GRE Tunnel established between internal and DMZ routers with the tunneld ACCORD between the branch and the router in the DMZ.
-
Backup of the GRE Tunnel using the address IP of Seconadary
Is it possible to configure a GRE Tunnel to backup using an IP of Seconadary address on the WAN interface. The router is a
Cisco 871. Any help would be greatly appreciated.
Thank you.
Nicholas
I'm not sure it would work for use a secondary address on the WAN interface for a GRE tunnel. Maybe if you tell us more about what you're trying to do we could be able to help find alternatives that would work.
Two tunnels from the same interface (even though you could use a secondary address) to another router would not provide a backup, if they work at all. Work of two tunnels of the same interface of router (and two using the main address) fairly well if they go to different remote routers, and it is a common way to provide backup for the GRE tunnels.
HTH
Rick
-
Multicast over GRE tunnel traffic
Hi guys,.
I have a connection via ISP connection point to point BGP on a connection of 100 Mbps between the branch and the central office.
I set up in two cisco routers with ios security advance 2801 a tunnel WILL running the ospf Protocol so I can share the multicast traffic for streaming between the two sites, but I am only able to get 6 Mbps out of the tunnel between the sites. I have configured multicast PIM sparc-mode to transport video traffic above the tunnel.
Is there a limit on the GRE tunnel, could it be MTU, or perhaps other issues anyone can help me solve this question guys?
Hello
There is a lot of discussion about the limitations of bandwidth on the tunnel interface. But most of the discussions flow seems to be linked to the limitation of the software on the device.
Issues could be related to MTU. Have you enabled PMTUD on the tunnel interface? If this is not the case, turn it on, as it recommended on the tunnel interface.
HTH.
Evaluate the useful ticket.
Kind regards
Terence
-
VPN3000 as an end of GRE tunnel
Dear all,
Is it possible for a VPN3000 to close a GRE tunnel by its own interface (private or public)? As long as I see in the GUI, looks like there no option for config one end of GRE tunnel. You can configure a GRE filter, but it comes through a GRE traffic, I'm right?
Best regards
Engel
Engel,
You can not cancel a Grateful for lan-to-lan tunnel based on a hub (as in IOS). Protocol PPTP uses GRE as the transport protocol, which supports a concentrator of VPN3K (and therefore filters and debugs for GRE)
Hope that answers your question
Jean Marc
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