From: Sergey Golovanov (sergey.golovanov@iementor.com)
Date: Tue Jan 23 2007 - 04:28:50 ART
Hello Ben,
can you please post "show int" output of both interfaces?
Thanks
--------------------------------------------------------------------
Sergey Golovanov, CCIEx5 (R&S/Security/Voice/Service Provider/Storage)
"Please, don't ask me for my ccie #, there are reasons why I can't release it"
ieMentor Instructor and Content Developer
sergey.golovanov@iementor.com
http://www.iementor.com
> -------Original Message-------
> From: Ben Zheng <bzheng8989@yahoo.com>
> Subject: Cannot receive CDP packet due to checksum error
> Sent: Jan 22 '07 20:07
>
> R1 (C2600) and R2 (C2800) is back-to-back connected. CDP are enabled on both
> routers
>
> R1 can see CDP neighbor R2 properly
>
> R1#sh cdp nei
> Capability Codes:
> R - Router, T - Trans Bridge, B - Source Route Bridge
> S -
> Switch, H - Host, I - IGMP, r - Repeater
> Device ID Local Intrfce
> Holdtme Capability Platform Port ID
> R2 Fas 0/0
> 142 R S I Cisco 2811Fas 0/1
>
> However, R2 cannot see the CDP
> neighbor R1.
>
> Turn on debug CDP on R1 and R2, it shows that R1 can sent and
> receive CDP properly, but R2 can only sent CDP. R2 cannot receive the CDP from
> the neighbor. The debug on R2 shows the checksum error in receiving CDP
> packet:
>
> *Jan 23 00:55:01.215: CDP-EV: Bad checksum in header
>
> It can also be
> confirmed from the output of sh cdp traffic on R2
>
> R2#sh cdp traffic
> CDP
> counters :
> Total packets output: 12, Input: 0
> Hdr syntax: 0,
> Chksum error: 12, Encaps failed: 0
> No memory: 0, Invalid packet: 0,
> Fragmented: 0
> CDP version 1 advertisements output: 0, Input: 0
> CDP version 2 advertisements output: 12, Input: 0
>
> How can I make CDP on R2
> work properly?
>
> R2#sh run int fa0/1
> Building configuration...
> Current
> configuration : 119 bytes
> !
> interface FastEthernet0/1
> description Link to R1
> ip address 10.12.1.2 255.255.255.0
> duplex auto
> speed auto
> end
>
> R1#sh run int
> fa0/0
> Building configuration...
> Current configuration : 119 bytes
> !
> interface
> FastEthernet0/0
> description Link to R2
> ip address 10.12.1.1 255.255.255.0
> duplex auto
> speed auto
> end
>
> Thanks,
>
>
> Ben
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This archive was generated by hypermail 2.1.4 : Thu Feb 08 2007 - 23:46:57 ART