LLDP is the non proprietary version of CDP. This discovery protocol has applications that can make an administrators life much easier. Now with two physical devices I am going to implement LLDP on JUNOS with the EX-2200 and SRX110. First of all we need to note that the SRX hasvLLDP off by default. The EX has it enabled by default.
Enabling LLDP is not a hard but some considerations have been made. I personally would not like to enable it by default globally on a firewall. I don’t mind this on a switch that is internal to your enterprise. If it was a DMZ firewall or switch you should control who sees what. To allow it per interface you just denote what interface in the command.
[email protected]> show configuration protocols lldp interface all;
This default on the switch is okay as my switch is an internal device. Time to enable LLDP on the interface fe-0/0/7 of the SRX.
[email protected]# set protocols lldp interface fe-0/0/7.0
Now both of our devices have active LLDP, it is time to check out what our SRX and EX sees.
[email protected]> show lldp neighbors Local Interface Parent Interface Chassis Id Port info System Name fe-0/0/7.0 - 08:81:f4:a9:14:80 ge-0/1/0.0 EX2200-C
Now from the other side.
[email protected]> show lldp neighbors Local Interface Parent Interface Chassis Id Port info System Name ge-0/1/0.0 - b0:a8:6e:66:e2:40 fe-0/0/7.0 SRX110
There we go. Easily configured and extremely helpful. I find LLDP useful when applied carefully. If you work in a secure environment I would suggest enabling it on a need to know basis!