cdp uni-directional traffic

[sg_network]

We are migration new chassis for Distribution and Access..

two Cat6 are running HSRP via Trunk with 10 Access switches..

All switches able to see the CDP.. only one of cat 6 did not able to see cdp neighbor..

cat6k1#sh cdp nei

Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge

S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone

Device ID        Local Intrfce     Holdtme    Capability  Platform  Port ID

cat6k1#sh cdp tra

CDP counters :

Total packets output: 321, Input: 0

Hdr syntax: 0, Chksum error: 0, Encaps failed: 0

No memory: 0, Invalid packet: 0, Fragmented: 0

CDP version 1 advertisements output: 0, Input: 0

CDP version 2 advertisements output: 321, Input: 0

the other side of network able to see cdp neighbor..

I can able to ping all switches including cat6k_1...

is there any missing point?

[andtoth]

Hi,

Did you try upgrading to latest IOS version?

Make sure links are not unidirectional with UDLD.

Check if control-plane policing is blocking CDP.

Andras

[yelynntun]

hi john,

recently, we also encountered same problem on the network that has been running for a few years.

my cat6k is using c6sup22-js-mz.121-27b.E1.bin and still trying to figure out what's happening.

rgd

ye lynn