Routing

[SathishkumarSaravanan0348]

Hi All,

I was enabled the ip route in one of the core switch as below.

ip route X.X.X.X 255.255.255.255 X.X.X.X name SSA track 123

ip route X.X.X.X 255.255.255.255 X.X.X.X name SSA track 123

What is the purpose of track 123 here ?

Thanks.

[Georg Pauwen]

Hello,

tracking is typically used in conjunction with an IP SLA. Do you have one in your configuration (post the full config in case you are not sure). 

[Giuseppe Larosa · Accepted solution]

Hello Satish,

the track 123 is a reference to tracking object 123.

Depending on the configuration of the track 123 object it it will be TRUE or FALSE when a monitored object like an IP SLA is in state up or down. Usually when the monitored object is up the track is TRUE.

If the monitored object fails the track 123 becomes FALSE and both the static routes that refer track123 will be removed from the IP routing table.

This kind of configuration allows for failover over backup static routes when the tracked object fails (typically an IP SLA).

Look in the configuration for finding the configuration of the track 123.

Hope to help

Giuseppe

[SathishkumarSaravanan0348]

Thanks for the update. I have an another query. I am still confused with the below 2 comments. Could you clarify.
1. Sh ip arp- displays the ip add of the connected device.(MAC to IP)
2. Sh cdp neigh- displays the conn devices.

Is there any significant difference between the two?

[Giuseppe Larosa · Accepted solution]

Hello Satish,

show cdp neighbors show the neighbor devices directly connected to your router or switch that speak CDP protocol (Cisco devices or third party IP phones or Cisco SW ip phone running on a PC).

CDP works at OSI layer2.

show ip arp

provides the mapping between IP addresses of connected IP subnets and their respective MAC addresses according to ARP protocol.

ARP provides information to map OSI Layer 3 (IP address) to OSI layer 2 info (MAC address)

A PC connected via a switch to a router can have an ARP entry, but it is not a CDP neighbor on the router.

So the two commands provide different information.

Hope to help

Giuseppe

[SathishkumarSaravanan0348]

Thanks mate.