When I type show neighbors on C5K switch, it is not showing the IP of the uplink switches.

When I type show neighbors on C5K switch, it is not showing the IP of the uplink switches. What is missing configuration I need to add to my C5K switch?

5 replies

Userlevel 2
Have you discovery protocols enabled on both switches?

Try "show lldp" and "show cdp". There ist also Cisco Discover Protocol, try "show ciscodp".

When I do a "show neighnors", I see the IPs with Type cdp, so I think, cdp has to be enabled.

Hope this helps.

Regards, Ralf
Userlevel 4
There are a number of reasons that this happening but lets start with the protocols in place
there is cdp, ciscodp and lldp
The standard is LLDP
To start LLDP on the C5 is set to Auto by default but it needs someone to talk to it via lldp( like a phone ir another switch
The easiest was to get the information is to start the conversation
What is usually do provide the basic's and then let the customer to decide if they want more than tge basic ip and say mac
so i suggest the following
set lldp port tx-tlv ?
this gives you a list of options ( in the lab i select all but you may want

I provided a list below ( please note my image may not be up to date)
but you are looking for mgmt-addr, so your command would be something like this
set lldp port tx-tlv mgmt-addr ( port # or for all ports *.*.* )
please note that if the other side of the link does not support the feature then you will get nothing
-There is another bonus for you from me
afte setting this up on your switch, try this command (for local and remote -information) you will like the feedback
show lldp port remote-info ge.x.x
going back to our question, the list below should help you
(su)->set lldp port tx-tlv ?

all Set all TLVs
gvrp Include gvrp TLV
lacp Include lacp TLV
link-aggr Include link aggregation TLV
mac-phy Include duplex and bit rate TLV
max-frame Include maximum frame size TLV
med-cap Include med capabilities TLV
med-loc Include med location TLV
med-poe Include med power TLV
med-pol Include med network policy TLV
mgmt-addr Include management address TLV
poe Include poe TLV
port-desc Include port description TLV
stp Include stp TLV
sys-cap Include system capabilities TLV
sys-desc Include system description TLV
sys-name Include system name TLV
vlan-id Include vlan id TLV

Good Luck,
Jason Parker
Userlevel 2
I would NOT recommend you to enable LLDP, in the past sometimes there where LLDP memory leaks that crashes the system. Use CDP and CiscoDP to be sure for a stable system.
Userlevel 4
Adam has a good point but i would just like to add, that we just released an image that addresses that issue posted yesterday i would ask you to consider the upgrade but only if you are setting a group of ports. There are a list of issues addressed in the release notes also addresing LLDP traps. I actually wrote these bugs up and tested the fix
i would suggest just setting only the ports (such as neighbor switches and not pc ports as you do not need the settings on those ports
Thanks again to all, we are out to help everyone succeed
Yesterday I had the C5K uplinked to a D2 switch without IP address and the D2 is uplinked to a B3 switch with an IP address. That time show neighbors did not show up any uplink IP address connection. I moved the C5K and uplinked it to a B3 with an IP address and show neighbors now shows the uplink switch IP address on CDP and Ciscodp but no lldp.

I am prepping for dual S4 Core and Storage Switch Upgrade later this month and there are a lot of ground work still to be done. I want to make sure when I uplink the C5K to my new S4 the show neighbor will show the S4 IP address on the 10Gb connection. Thanks for everybody's comment and the note about lldp.