SNMP and DHCP requests on collector

Similar Questions

• Invalid field of SEC (seconds) on the DHCP requests sent by 9 X 2

  Hi all

  When I plug the phone to the switch (CISCO SGE2010P poe) the phone starts up, but when sends the FIRST dhcp request, it has a value of 29 seconds, so switch relay makes the backup DHCP server and get all the backup information when main is living.

  As can be read on the manual switch:

  "DHCP requests are relayed only if their DRY field is greater than or equal to the threshold value". SPA962 with SPA942, it is always true. The initial time (used to subtract) should be network time and no start.

  Thank you

  I solved this problem:

  The phone was right, the problem is to have activated Spannin tree on the switch, because it will not be before up to 30 seconds broadcast packets to get the link.

  Thank you

• WES610N has not managed a DHCP requests of beneficiaries to E3000?

  I can not get my WES610N to transmit DHCP requests via wireless to my E3000 router.

  If I connect physically E3000-> WES610N-> laptop, it'll pass the DHCP request and get network access to the laptop.

  As soon as I use the WAP as provided for in my media center with Wireless between E3000-> WES610N a wired connection between WES610N-> mobile/XBOX/PS3 none of the DHCP requests are passed along, and no access to the network is provided.  The wireless signal remains strong to WAP, and I show the client wireless and assigned address DHCP at the end of the router.

  I am running the latest firmware to factory on the E3000 (tried DD - WRT with no luck).  Wireless security is WPA2-Personal with AES and a MAC filter to allow only a list of wireless clients.  Run auto-channel and connected to the 5 GHz signal.  I even tried to add MAC addresses to filter for customers physically connected to WAP with no luck.

  Is there something I'm missing here, or is this a common problem?

  Thanks in advance for any help!

  Of course, it was something simple that fixed...  I had checked the firmware on the router was in effect, but for some reason any it never came to mind to check the firmware on the bridge itself.

  I received a chat session with the help of Cisco and they gave me the link for the updated for the WES610N and the WET610N firmware.  After a re-flash all my current configurations for network addresses, authentication and appointing remain - so all I had to do was to remove the wired connection to router at the bridge (which was required to connect and perform the flash) and give it a try.

  Initially, with the bridge still sitting next to the router it would drop and re - connect about every 20 seconds, an improvement, but still not acceptable.  As soon as I moved it 10 + feet away from the router (as shown) the connection remained strong and is more randomly disconnected.  The final resting place has been to my media center, which is about 30 feet more far laterally and down a level in my house.

  After flash it now connects quickly, successfully passes DHCP queries on multiple devices, successfully conducts tests of speed/transfer and does not abandon the connection only once during a few hours of play.  The speeds are always disappointing, maxing out at about 70 MB/s on wirelessN - but that's a lot for streaming media and ~ 2 x more than my cable internet service can pull down.

  Anyway, here is the link to the firmware if you are still with me after this long explanation:

  http://homedownloads.Cisco.com/downloads/firmware/1224668058222/FW_WES610N_WET610N_1.0.05.004_201108...

• function of guard of source IP and dhcp DHCP scope of exhaustion (customer parodies other customers)

  Hello world.

  A dhcp server assigns ip address based on the mac address by equipment of the customer field in the dhcp packets.

  A potential attack is when a crowd of thugs mimics different mac addresses and causes the dhcp server to assign ip addresses until no ip address is left for legitimate host.

  For example, a host with mac1 h1 is designated by the ip address of the dhcp server as:

  199.199.199.1 mac1

  DHCP server has this entry in its database.

  Using hacking tools such as Yersinia or Gobbler can create a DHCP discover messages every time that create another mac for material scope of the client to the dhcp server, thereby causing a dhcp server to assign ip addresses because they are of legitimate dhcp to dhcp server discover messages with matching each another Mac in hardware of client addresses.

  You could use dhcp snooping and it will avoid that (exhaustion of dhcp scope) and configure the switch to check if the CBC mac fits the hardware address of the client in the dhcp message. But when even we can creat spoofed discover messages where mac src in the ethernet header will match the client hardware address in dhcp discovery message. It did not always overcome the problem.

  You might say use IP source guard characteristic but it really will prevent this problem from happening?

  Let me illustrate:

  H1 - f1/1SW - DHCP server

  Let's say that we have configured dhcp snooping on sw1 and f1/1 is untrusted port.  Switch a suite dhcp binding

  199.199.199.1 mac1 vlan1 f1/1

  Then, we configure source ip guard in order to validate the mac src and src ip against the dhcp bindings. When you configure keep source ip first, it will allow dhcp only if a host can request ip address and dhcp binding can be built. After that IP keep source will validate ip or mac src src or both against the binding.depending dhcp on how configure us source ip guard.

  In our case, we have configured source ip guard in order to validate the mac src and src ip against the dhcp binding.

  A dhcp connection is already created as:

  199.199.199.1 mac1 vlan 1 f1/1

  Now, using hacking tools Yersinia or Gobbler on h1, we create our first spoofed dhcp discovery message where mac src = mac2 ethernet header and client harware address = mac2 in dhcp discovery message. As the switch is configured with the function of guard of source ip and therefore allows dhcp discover message to pass through. DHCP server after you receive the message dhcp assigns another IP from the pool. The dhcp server has now after the entries:

  199.199.199.1 mac1

  199.199.199.2 mac2.

  We continue to spoofed dhcp to craft discover messages as described above and are dhcp server keep ip address assignment until exhausts the entire pool.

  So my question is how ip source guard in conjunction with dhcp snooping doesn't stop this attack does not happen? (IE DHCP scope exhaustion)

  I really appreciate your comments.

  Thank you and have a week.

  Hi Sara,.

  Ask was quite interesting. As far as I know that whatever it is port snooping untrusted won't let your fake dhcp server.

  You can take this query in the Sub forum of experts mentioned that is specific for dhcp snooping and source of guard.

  https://supportforums.Cisco.com/message/3689811#3689811

  Please assess whether the information provided is useful.

  By

  Knockaert

• SGE2010 - traffic relay and DHCP configuration

  Hei

  We bought just a switch SGE2010 we want to use to replace the switches in the control panel of our office. So far I managed to access the switch and assigned a static ip.adress on our net, but I can't get to our entry point switch relay traffic. I have a test machine that is configured with a static IP as well and tried the ok sign, but as soon as I put the switch between traffic is not relayed.

  The idea was to use this switch as a DHCP as well. But I thought it would be a start to get at least the traffic relayed before starting the dhcp part.

  Only configuration settings I have done factory settings are the following: (note that the IP is slightly adjusted, but consistent for reasons of confidentiality)

  Configuration of the IP4

  1. Assigned to a static ip address: 95.59.69.148
  2. Assigned a subpattern: 255.255.255.192
  3. Assigned to a user-defined gateway: 95.59.69.129

  DNS configuration

  1. Assigned to an ip address dns address: active 95.59.0.100
  2. Assigned to a dns ip address: 95.59.0.200

  All these settings are the default settings that we use when we assign a server with a static ip address, so it is not a pick up of our filtration dhcp server. So my main question is why on earth isn't it relay traffic?

  In addition, we are interested to kill the former (with stones, I hope) dhcp server and dhcp on the sge2010 configuration. The current dhcp is an operating system. X dhcp server (Yes a mac) with the following configuration:

  • (Dynamic ip) subnet
    From ip: 95.59.69.179
    Ending ip: 95.59.69.190
    Subnet: 255.255.255.192
  • Router ip: 95.59.69.129
    Rental time: 3 hours
  • The range 95.59.69.130 to 95.59.69.149 we set up manually on the servers, hardware, etc.
  • DNS server: 95.59.0.100 & 95.59.0.200
    Default search domain: No. - dns - available.example.com
  • And then we have a group of static mappings to Mac-addresses
    ip address: 95.59.69.150
    IP: 95.59.69.178

  I tried to see in the configuration where I could the mappings static spesify range etc, but I can't say it got me anywhere. So my second question is how to install a server dhcp of Eric as a designated above?

  It's nice to finally convince the CEO to move the dhcp to a better metal, but it's not as nice having a hard time setting up. I would apprecitate every possible leeds and suggestions since I'm kinda stuck.

  Thanks in advance

  Rafn.R

  Hello

  My SGE2000P forwards DHCP requests on my DHCP server.

  I used my default VLAN1 as an interface routed to unicast request DHCP relay on my server (router ISR UC520) that resides on that VLAN 1.

  My interface Vlan 1 on my SGE2000P has an IP 192.168.10.254.

  My gateway address for potential hosts in VLAN 2 IP will be the ADDRESS IP I AI ASSIGNES to VLAN 2, because the PC or the IP hosts connected to VLAN2 will use IP VLAN2 interface as the gateway. It's just how it works!

  Hosts of PC on VLAN 2 need of a default route and they use the IP I assigned to VLAN2 as their next jump out VLAN2 on the real world.

  This address can be seen below.

  

  DHCP relay is enabled with the option 82

  

  I chose VLAN2 as an interface VLAN, as shown below.

  

  I have two ports not signposted in the VLAN2, and I joined an IP host to G1 so that I can test the DHCP relay.

  

  I get the following debug output from my dhcp server, so I know the relay is working.

  002624: 19:40:08.575 Dec 5: DHCPD: looking for expiry of the leases.

  002625: 19:40:58.408 Dec 5: DHCPD: DISCOVER notification to:

  002626: 19:40:58.408 Dec 5: DHCPD: htype 1 CHADRR 0025.84d8.d008

  002627: 19:40:58.408 Dec 5: DHCPD: id remote 020a0000c0a80a0101080001

  002628: 19:40:58.408 Dec 5: DHCPD: id circuit 00000000

  002629: 19:40:58.408 Dec 5: DHCPD: see if there is a specified internal pool class:

  But I must confess that I have opened a case on it with the Small Business Support Center, because I think I can see something wrong on my DHCP server debugging.

  But the key is that I see the router WAN/DHCP server, see the query from DHCP.

  The only way to the broadcast DHCP requests can get to the DHCP server, if the switch SGE2000P takes these DHCP broadcast requests and unicast these or relay to my server DHCP IP address 192.168.10.1.

  So in other words he tries to relay DHCP.

  I would ask you to please check the SGE2010 Administrator's guide because it clearly shows how to configure the DHCP on the SGE2010 relay.

  Even if the screen capture shows and the old version of the code below.  I have day my SGE2000P tonight at the generally available (GA) version of the code.

  

  Just outa interest, if you telnet to the switch, is your mode of layer 3 or Layer 2 switch.

  I can also say from your screenshot that your uplink ports are in overlay mode.

  Maybe if you don't use stacking, you can set your switch to the layer 3 mode and standalone mode

  Best regards, Dave

• Incorrect host name length ASA DHCP Request

  I have an ASA 5505 with software version 8.2 (1). It deploys DHCP requests to the clients that connect to the ASA IPSec. The DHCP protocol please packages that the ASA did have a '00' extra added to the hostname field, and the length field is the size of the hostname + 1.

  The DHCP server is a Microsoft Server 2003 and this causes the host name be registered with an unknown character who is listed under the hostname []. Then, when server 2003 tries to update the DNS record, it fails because of the invalid character in the host name.

  Is anyway to have the ASA have the right length for the host in the DHCP package name field or a workaround that will solve this problem?

  Hi Mark,

  That's exactly the problem described in, here's a copy of the bug release notes:

  Symptom:
  
  When VPN Clients connect to the ASA the ASA inserts an extra character or carriage return in the DHCP scope which causes the users' application to display dhcp information on two lines as opposed to one; the extra character causes a line feed on address resolution and automated tools can't handle the result.
  This is also noticed as an extra symbol that looks like a box/carriage return added to the "Name" Field within the Windows 2003 Server > DHCP > Scope > Address Leases.
  Conditions:
  ASA using Windows 2003 Server as external DHCP Server.
  
  VPN Clients update DNS using DHCP protocol through ASA to external Windows 2003 DHCP server.
  
  ASA has "dhcp-client update dns" or "dhcp-client update dns server none" configured.
  Workaround:
  Don't update DNS through DHCP to an external server, i.e. configure "no dhcp-client update dns".
  Further Problem Description:
  The ASA sends the DHCP server a packet with malformed DHCP option 81 (Client Fully Qualified Domain Name) which causes the Windows 2003 Server to add a character to the 'Name' field in the DHCP Scope Address Leases seen on the Server.  This character looks to be a carriage return.
  
  
  
  
  You have 'dhcp-client update dns' configured on your ASA?
  If so, could you delete and see if the ASA always sends option 81?
  Kind regards
  Nicolas
  		   

• Equium M50-244 has bluescreens and password requested

  Hi all
  I need your help here please, my wife Equium M50-244 just froze after 15 min. I thought out the battery could solve the problem, only now when you turn on the laptop I get blue screen and a request for password that was not supplied with the computer.

  Can anyone help before she beat the life out of me (great she´s).

  Hi friend

  I hope that you´re still alive and your wife didn t just have you beat :)

  Please give more information about your problem. It seemed the first time? And what operating system you have? Have you recently updated some drivers or installed new hardware?

  And no matter what, with this password? I mean that a password does not seem fair to nowhere! Where is this password? BIOS or Windows?

  Man, give a few specific questions with plenty of information, so people here can help you.

  Welcome them

• Requirement of DNS and DHCP Server Essentials 2012 home

  I have a Server Windows Essentials 2012 acting as DNS and DHCP server with a domain name for backups etc on my home network. It's that everything works fine, no errors, no problem. Works well actually, telling me when the children did not install updates or restarted.

  I have two groups of users. My sons step, 10 and 12, which I want to use OpenDNS as a provider external DNS with a policy very, very limited and my wife and me who want to use indications of root or Google DNS or any other DNS provider. Others, specific devices no user (box of the xBox, WII, Satellite, TV, CCTV etc.) can use.

  Before the 2012 server, I had a 2 k 3 server running in a virtual machine for DHCP, alone and put my wife and my devices on static reservations with the just and external DNS provider used OpenDNS as the default scope, DNS. Unfortunately different bits of domain services 2012 don't seem to work unless the server of 2012 is the first DNS server listed on client machines (backups failed. Impossible to find other local computers). Currently, this means that we are all using OpenDNS.

  What I would like is a way to say 2012 to send adult group DNS queries to another DNS provider and leave the rest at default to OpenDNS, while still having them register in the original DNS domain. Any suggestions?

  This issue is beyond the scope of this site and must be placed on Technet or MSDN
  http://social.technet.Microsoft.com/forums/en-us/home

  http://social.msdn.Microsoft.com/forums/en-us/home

• Difference between SNMP and agent installs

  I'm curious to know the differences between the use of SNMP and agents.

  We have a Ubuntu Server that must be monitored don't know the best way to monitor.

  Hey Evan,

  Here are the major issues. NMS you currently have is the snmp network Foglight solution. If you were to buy FMS, you could install the NMSAgent.car that retrieves data of the NMS system, you already have running.

  I hope it's her. Networking FMS cartridge extracts data from SMN via web calls.

  Best regards

  Jonas

• L3 - SG300 - 28 p and DHCP

  Hi all

  I'm having a bit of difficulty up a SG300 - 28 p to L3 and DHCP. I will attach a basic network diagram and a very short list of my needs.

  I'm building a temporary network for a company event 1 day that I can't make it work in our office "Lab".

  L3 - SG300 - 28 p connects to our provider using a connection of the SFP.

  I have to be able to address IP DHCP 300 + using the SG300 - 28 p

  My problem is that I can ping my 2 machines test (manually configured IP) about 172.16.0.3 and 172.16.0.4, but cannot ping after the (internet) referral. Also DHCP distributes no intellectual property for the range 172.16.0.10 - 172.16.1.200

  VLAN 1 is set to 10.2.2.20 access port (to the provider through a connection on port 28 FPS)

  VLAN 100 is 172.16.0.2 access port (ports 1-26)

  I have the WLC and WAP tri...

  Is the set of even possible? I know that the EQ network is a bit budget for users, but for a one day business event I just do not have a budget for the purchase of switches better.

  Please excuse the gross chart.

  Thank you in advance.

  -RJ

  Thanks for the reply.

  With the information that you have provided, it seems the only part missing is the way return the unit for service providers. Unfortunately there is no way around that, and no, you will not be able to put anything between the two, because the device doing the NATting is unity of suppliers.

  I think that what is happening is that traffic is actually the side provider, but there is no way to do so as soon as the provider is not a route for the subnet in 172.16.x.x.

  Out of curiosity, why do you use a VLAN for the devices connected to the SG300? Could you use the 10 subnet Ip addresses? If you do this, you will not need to have a route back from the supplier, as all devices will be on the same subnet.

• Series of unmanaged switches 100 and DHCP

  Hi all, we have a router RV082 switch 8 ethernet ports, it is actually 8 lan with a DHCP address assignment devices (router is used as switch/router and DHCP server).

  Now we need to increase the number of attached LAN devices (other pc, printers, etc.), and we think buy Cisco 100 ethernet switch Series 16 or 24 ports to connect to RV082.

  In this case RV082 will be able to assign DHCP addresses for devices connected to the eth switch ports?

  Thanks in advance.

  Hi Loris, yes it is not a problem. You should be able to switch on a lan port, connect computers to the switch and things should be OK.

  -Tom
  Please mark replied messages useful

• SNMP and cisco Aironet 1131AG

  We have a wireless control system, 3 WLC and 190 APs. I need to listen to 802.11 radios via SNMP. The system is running with LWAPP and APs are not accessible via SNMP (no response trying to access). I'm trying to send traps on the Server SNMP (Zabbix) but to disable the WLC 802.11 Radio, I don't see any trap regarding the status of the Radio or the admin down.

  Are you looking for it any method to monitor the status of the radio via SNMP?

  Thanks in advance,

  OLAF

  Hi Olaf,.

  Lwapp APs are not snmp manageable but controllers takes care of this. You can query the WLC via SNMP and it will give you the status of all access points radio.

  I suggest to use the tool of Cisco's MIB browser learn more about AIRESPACE mib that uses the WLC.

  Nicolas

• Try to install 6 LR and configure request password.  Used my adobe password, but it won't take it.  Failed to install.

  Try to install 6 LR and configure request password.  Used my adobe password, but it won't take it.  Cannot install

  Use your administrator password, because this message is probably your computer asks you to verify that you are authorized to install

• Svchost and dhcp client slows windows xp

  I've recently updated the image into my netgear router. The device is connected via a powernet connection.
  But since the upgrade and also a little before the upgrade, the svchost in windows xp that runs the thread of the dhcp client has been slowing all processes within windows xp sp3.
  It has now got to the point that I have to wait more than 2 hours before I can get on the internet with any real effect. It costs money to my company and I am sure that Mr. Gates would be more upset if his employees only had 1/2 hour of work time each day due to an unusable operating system.
  I don't have the original image file to down-grade of the router. Can anyone suggest a fix for this problem?

  I know that this problem has been reported for many years through different websites and microsoft have still not managed to solve this problem.

  Hi tmd63,

  Follow these methods.

  Method 1: Follow these steps:

  Step 1: Start the computer in safe mode with network and check if the problem persists.

  Step 2: If the problem does not still in safe mode, perform a clean boot to see if there is a software conflict as the clean boot helps eliminate software conflicts.

  Note: After completing the steps in the clean boot troubleshooting, follow the section How to configure Windows to use a Normal startup state of the link to return the computer to a Normal startupmode.

  After the clean boot used to resolve the problem, you can follow these steps to configure Windows XP to start normally.

  (a) click Start, run.

  (b) type msconfigand click OK.

  (c) the System Configuration Utility dialog box appears.

  (d) click the general tab, click Normal startup - load all services and device drivers and then click OK.

  (e) when you are prompted, click restart to restart the computer.

  Method 2: Follow the steps in the article.

  How to troubleshoot a network home in Windows XP

  In Windows network connection issues

  Method 3: Update the latest drivers for network.

  How to manage devices in Windows XP

• Firewall XP slows telnet and pop requests to other servers

  with xp firewall WE telnet takes about 10 seconds to connect to my linux server. workstation on the same POP form xp server takes about 10 seconds
  with xp firewall OFF it connects instantly
  I've tried doing the fomr even another machine winxp and this problem does NOT occur. So it seems that I have a machine that has a firewall problem
  all windows updates and patches have been installed
  This dbeen has now lasted about a year. time to find out how to fix :)

  Well, for all those interested, ive worked the definitive answer to this problem underway long myself for "xp firewall slows down applications to other telnet servers and pop.

  After doing a few capture and analysis of communication between my workstation and server, I noticed the server sending some 113 applications port to my work in response to the pop stations and requests for telnet access and I think than ftp also.

  Port 113 refers to "ident" username for authentication on the servers running of authentication such as "identd". If the workstation does not respond, then it may delay the connection. The solution is to put an exception on the firewall of my computer such as windows xp firewall to allow port 113 through.

  To do, it is very easy for all of us here are the steps for your Windows XP workstation:

  Start | Control Panel | Windows Firewall | Exceptions | Add Port. 113 TCP Port number. Comment: The authentication of the user name to the server with the ident Protocol

  So there you have it. Finally... INSTANTLY connect and response of the connection for pop, telnet and ftp :)

  Edward Jozis