GRE tunnels

Similar Questions

• IGP and GRE Tunnel

  GRE.png

  

  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:

  1. What is the standard in this topology using the two connection for iGP peering or just tunnel in the real world?
  2. 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

  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.
  2. 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)

• 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

• 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)

• 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 310818168/50

  I 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 upwards

  Site-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
  end

  Site-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 encryption

  C - 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 his

  Interface: Ethernet1
  Tag crypto map: IPVPN_MAP, local addr 74.WW. XX.35

  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.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 0

  local 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: ACTIVE

  the 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: ACTIVE

  outgoing 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 0

  local 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: ACTIVE

  the 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: ACTIVE

  outgoing 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 policy

  World 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
  !
  end

  Any 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.

• NAT &amp; GRE Tunnel

  Hello

  I have a test installation routers 2 with a GRE tunnel which works very well in the test configuration. My question is if I transfer this config for direct mounting how I would exempt traffic over the tunnel WILL be natted? Everything else is the traffic destined for the internet should be tapped to the external interface. Would need a road map for this?

  Thank you

  R1

  --

  interface Tunnel0

  IP 192.168.200.2 255.255.255.0

  dissemination of IP ospf network

  KeepAlive 10 3

  source of tunnel FastEthernet0

  tunnel destination 1.1.1.1

  crypto mymap map

  interface FastEthernet0

  Outside of the Interface Description

  1.1.1.2 IP 255.255.255.0

  automatic speed

  crypto mymap map

  R2

  --

  Tunnel1 interface

  192.168.200.1 IP address 255.255.255.0

  dissemination of IP ospf network

  KeepAlive 10 3

  source of tunnel FastEthernet0

  tunnel destination 1.1.1.2

  crypto mymap map

  interface FastEthernet0

  Outside of the Interface Description

  IP 1.1.1.1 255.255.255.0

  automatic speed

  crypto mymap map

  Yes you are right.

• Significant decline in performance on the GRE tunnel after using cryptographic protection

  Hi all

  I have two G1 RSR (1811 and 1812) who have a GRE tunnel between them.

  Without any encryption protection I received about 3.6 MB/s in regular transfers of Windows SMB. After using cryptographic protection of the tunnel I'm now only 2.7 MB/s transfers of same.

  No idea as to why this is?

  My conclusions:
  According to this http://www.cisco.com/web/partners/downloads/765/tools/quickreference/vpn... the AES crypto fixed return of the 1800s is 40 MB/s.
  The increase in overhead of cryptographic protection shouldn't be the problem I tried to test the transfers on the tunnel without protection and 'ip tcp adjust-mss 800' of the tunnel. There was only a small performance drop here, not as much as with the crypto.
  I tried several sets of cryptographic transformation, they all give the same performance as long as they are made in the material.
  ISAKMP is always done in the software? I can't get it to show its is done at the hardware level, regardless of isakmp policy.

  IP MTU on both interfaces of tunnel are 1434 with cryptographic protection.

  My config:

  crypto ISAKMP policy 10
  BA aes 256
  sha512 hash
  preshared authentication
  Group 20
  isakmp encryption key * address *.
  !
  Crypto ipsec transform-set ESP-AES256-SHA esp - aes 256 esp-sha-hmac
  transport mode
  !
  Profile of crypto ipsec VPN
  game of transformation-ESP-AES256-SHA
  !
  Tunnel10
  IP 10.251.251.1 255.255.255.0
  no ip redirection
  no ip proxy-arp
  load-interval 30
  source of tunnel FastEthernet0
  tunnel destination *.
  tunnel path-mtu-discovery
  Tunnel VPN ipsec protection profile
  !

  Output:

  ISR1811 #sh crypto ipsec his
  Interface: Tunnel10
  Tag crypto map: addr Tunnel10-head-0, local *.

  protégé of the vrf: (none)
  ident (addr, mask, prot, port) local: (* / 255.255.255.255/47/0)
  Remote ident (addr, mask, prot, port): (* / 255.255.255.255/47/0)
  current_peer * port 500
  LICENCE, flags is {origin_is_acl},
  #pkts program: 683060, #pkts encrypt: 683060, #pkts digest: 683060
  #pkts decaps: 1227247, #pkts decrypt: 1227247, #pkts check: 1227247
  compressed #pkts: 0, unzipped #pkts: 0
  #pkts uncompressed: 0, #pkts compr. has failed: 0
  #pkts not unpacked: 0, #pkts decompress failed: 0
  Errors #send 0, #recv 0 errors

  endpt local crypto. : *, remote Start crypto. : ***
  Path mtu 1500, mtu 1500 ip, ip mtu IDB FastEthernet0
  current outbound SPI: 0x8D9A911E (2375717150)
  PFS (Y/N): N, Diffie-Hellman group: no

  SAS of the esp on arrival:
  SPI: 0xD6F42959 (3606325593)
  transform: aes-256-esp esp-sha-hmac.
  running parameters = {Transport}
  Conn ID: 45, flow_id: VPN on board: 45, sibling_flags 80000006, crypto card: head-Tunnel10-0
  calendar of his: service life remaining (k/s) key: (4563208/1061)
  Size IV: 16 bytes
  support for replay detection: Y
  Status: ACTIVE

  the arrival ah sas:
  SAS of the CFP on arrival:

  outgoing esp sas:
  SPI: 0x8D9A911E (2375717150)
  transform: aes-256-esp esp-sha-hmac.
  running parameters = {Transport}
  Conn ID: 46, flow_id: VPN on board: 46, sibling_flags 80000006, crypto card: head-Tunnel10-0
  calendar of his: service life remaining (k/s) key: (4563239/1061)
  Size IV: 16 bytes
  support for replay detection: Y
  Status: ACTIVE

  outgoing ah sas:
  outgoing CFP sas:

  ISR1811 #show in detail his crypto isakmp
  Code: C - IKE configuration mode, D - Dead Peer Detection
  NAT-traversal - KeepAlive, N - K
  T - cTCP encapsulation, X - IKE Extended Authentication
  PSK - GIPR pre-shared key - RSA signature
  renc - RSA encryption
  IPv4 Crypto ISAKMP Security Association

  C - id Local Remote I have VRF status BA hash Auth DH lifetime limit.
  2015 * * ACTIVE aes sha5 psk 20 12:42:50
  Engine-id: Conn-id = SW: 15
  2016 * * ACTIVE aes sha5 psk 20 12:42:58
  Engine-id: Conn-id = SW: 16
  IPv6 Crypto ISAKMP Security Association

  Use of CPU for the transfer with crypto:

  ISR1811 #sh proc cpu its

  ISR1811 09:19:54 Tuesday Sep 2 2014 THIS

  544444555555555544444444445555544444555556666644444555555555
  355555000001111133333888884444444444333333333377777666662222
  100
  90
  80
  70
  60                                          *****     *****
  50 ****************     **********     ************************
  40 ************************************************************
  30 ************************************************************
  20 ************************************************************
  10 ************************************************************
  0... 5... 1... 1... 2... 2... 3... 3... 4... 4... 5... 5... 6
  0 5 0 5 0 5 0 5 0 5 0
  Processor: % per second (last 60 seconds)

  ISR1812 #sh proc cpu history

  ISR1812, Tuesday 09:19:24 Sep 2 2014 THIS

  666666666666666666666666666666666666666666655555444445555544
  777888883333344444555555555566666777770000055555777776666666
  100
  90
  80
  70 ********          ********************
  60 ************************************************     *****
  50 ************************************************************
  40 ************************************************************
  30 ************************************************************
  20 ************************************************************
  10 ************************************************************
  0... 5... 1... 1... 2... 2... 3... 3... 4... 4... 5... 5... 6
  0 5 0 5 0 5 0 5 0 5 0
  Processor: % per second (last 60 seconds)

  I think that this performance is what you should get with the legacy 18xx SRI G1. But the performance degradation is perhaps really a little too high.

  For ISAKMP, there is no problem with that. The amount of protected data is too small to have one any influence.

  As a first test, I would remove the GRE encapsulation by setting "mode ipsec ipv4 tunnel" on the tunnel interface and compare if the results improve.

• 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.

  vpn_over_gre_tunnel.jpg

  

  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

• An interface of multipoint GRE tunnel on two physical interfaces?

  Hi all

  I use DMVPN double single cloud VPN network of hubs.

  Our shelves (C831 SRI) are connected to the dynamic DHCP ISP and dynamic PPPoE ISP.  I want to install a temporary kit that fits anywhere.  Here is the configuration of my my ISP PPPoE tunnel:

  interface Tunnel0
  bandwidth 1000
  IP 172.23.2.254 255.255.252.0
  no ip redirection
  IP mtu 1436
  property intellectual PNDH authentication xxxxxx
  map of PNDH 172.16.0.1 IP 230.2.2.1

  map of PNDH IP multicast 230.2.2.1
  map of PNDH 172.16.0.2 IP 230.2.2.2
  map of PNDH IP multicast 230.2.2.1
  PNDH id network IP-900001
  property intellectual PNDH holdtime 300
  property intellectual PNDH nhs 172.16.0.1
  property intellectual PNDH nhs 172.16.0.2
  delay of 1000
  source of Dialer1 tunnel
  multipoint gre tunnel mode
  tunnel key xxxxxx
  Tunnel MyIPSecProf ipsec protection profile

  For my ISP DHCP, I only change the Ethernet1 tunnel source.

  Is it possible to configure tunnel interfaces different related 2 on 2 physical interfaces (like: 1 Ethernet1 and 1 in Dialer1).  The challenge is that I can not change the configuration of hubs at all.  So I can't put the ip address of the tunnel in 2 different subnet.  There is only 1 tunnel on the hub interface

  Someone has an idea?

  Thank you very much

  Yes, I see it now. Unnumbered IP will provide the interface to the MTR and tunnel interface you have is point-to-multipoint. I'm afraid that there is no good solution to your needs.

  Kind regards

  Lei Tian

• GRE tunnel

  Hi - I'm trying to understand how the network described in the configuration http://pastebin.com/fM40vxcG is structured. I'm fighting for work on how I am connected to 10.144.254.1 before building a gre tunnel by using the node as a tunnel destination. Thank you very much

  concerning

  Vladimir

  Hello Vladimir,.

  I checked your link.

  I was you I wouldn't stick my Pwd VPN on a public forum, which is not really sure (unless you used a collar). If this isn't the case, you can edit your post and point to another link with pw stripped and can change the public ip addresses as well.

  Regarding your configuration, you have an encryption card configured with an ACL that match the tunnel.

  So in the end, your GRE tunnel using the private IP address is encapsulated in an IPSEC Tunnel using public IPS (see set crypto map peer): then you have a tunnel tunnel.

  I can't tell you the object of this since I do not know your topology.

  Hope this helps,

  Bastien.

• 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

• GRE tunnels and no gre

  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

• 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

• 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.