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cisco switch 4948 sends the wrong ipv6 protocol...

jiangcaixia
Level 1
Level 1

Hi,

I captured the cdp packet sent by the cisco switch 4948 and find the ipv6 protocol is wrong.

The full cdp packet is:

0100 0ccc cccc 001e f777 c64b 01fa aaaa 0300 000c 2000 02b4 ab90 0001 0024 626a 2d76 6d6b 7161 2d63 3439 3438 2d30 312e 656e 672e 766d 7761 7265 2e63 6f6d 0005 010a 4369 7363 6f20 494f 5320 536f 6674 7761 7265 2c20 4361 7461 6c79 7374 2034 3530 3020 4c33 2053 7769 7463 6820 536f 6674 7761 7265 2028 6361 7434 3530 302d 4950 4241 5345 4b39 2d4d 292c 2056 6572 7369 6f6e 2031 322e 3228 3436 2953 472c 2052 454c 4541 5345 2053 4f46 5457 4152 4520 2866 6331 290a 5465 6368 6e69 6361 6c20 5375 7070 6f72 743a 2068 7474 703a 2f2f 7777 772e 6369 7363 6f2e 636f 6d2f 7465 6368 7375 7070 6f72 740a 436f 7079 7269 6768 7420 2863 2920 3139 3836 2d32 3030 3820 6279 2043 6973 636f 2053 7973 7465 6d73 2c20 496e 632e 0a43 6f6d 7069 6c65 6420 4672 6920 3237 2d4a 756e 2d30 3820 3136 3a35 3620 6279 2070 726f 645f 7265 6c5f 7465 616d 0006 0012 6369 7363 6f20 5753 2d43 3439 3438 0002 0049 0000 0003 0101 cc00 040a 707b 3c02 08aa aa03 0000 0086 dd00 10fe 8000 0000 0000 0002 1ef7 fffe 77c6 7f02 08aa aa03 0000 0086 dd00 1020 0900 0000 0000 0000 0000 0000 0000 0100 0300 1747 6967 6162 6974 4574 6865 726e 6574 312f 3132 0004 0008 0000 0029 0009 0010 626a 2d76 6d6b 6e65 742d 7161 000a 0006 0001 000b 0005 0100 1200 0500 0013 0005 0000 1600 1100 0000 0101 01cc 0004 0a70 7b3c 001a 0010 0000 0001 0000 0000 ffff ffff

The bold fonts are the address value of the cdp packet. It contains three addresses: one ipv4 and two ipv6. There are:

0101 cc00 040a 707b 3c   ==> ipv4 protocol: 0xcc

02 08aa aa03 0000 0086 dd00 10fe 8000 0000 0000 0002 1ef7 fffe 77c6 7f  ==> ipv6 protocol: 0xaa aa03 0000 0086 dd

02 08aa aa03 0000 0086 dd00 1020 0900 0000 0000 0000 0000 0000 0000 01 ==> ipv6 protocol: 0xaa aa03 0000 0086 dd

However, the ipv6 protocol should be 0xaa aa03 0000 0008 00 according to http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm#xtocid12. So, is the above cdp packet wrong? Is there something wrong with the cisco switch 4948?

BTW, the platform is cisco WS-C4948.

The IOS version is: Cisco IOS Software, Catalyst 4500 L3 Switch Software (cat4500-IPBASEK9-M), Version 12.2(46)SG, RELEASE SOFTWARE (fc1)

Look forwards to your reply. Thanks!

Regards,

Caixia

1 Reply 1

paolo bevilacqua
Hall of Fame
Hall of Fame

CDP is a proprietary protocol, only partially documented. You can claim that something is wrong with it only if it cause a real problem ito you, and you have to do that throughout the Cisco TAC.

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