Solved: sh arp on router

mahesh18 · ‎03-31-2010

Hi all,

I did sh arp on router

2650xm#sh arp
Protocol Address          Age (min) Hardware Addr   Type   Interface
Internet 96.51.x.x          -   000f.8f6d.7e60 ARPA   FastEthernet0/0
Internet 192.168.1.40           95   000b.be59.cc60 ARPA   FastEthernet1/0
Internet 192.168.1.11          199   0015.e9cf.190b ARPA   FastEthernet1/0
Internet 192.168.1.10          224   000b.bece.bbc0 ARPA   FastEthernet1/0
Internet 192.168.1.1             -   000f.8f6d.7e70 ARPA   FastEthernet1/0
Internet 192.168.1.3             8   0026.c64a.b844 ARPA   FastEthernet1/0
Internet 96.51.145.70           38   0013.46d2.fb11 ARPA   FastEthernet0/0
Internet 96.51.144.1             0   0011.20a8.04a7 ARPA   FastEthernet0/0

Here 96.51.x.x is ip of fa0/0 interface of my router and it directly connects to cable modem

96.51.144.1 is my next hop route.

my question is why i see - under age for fa0/0 interface ip of my router and 0 for next hop ip 96.51.144.1 ?

They do not change remail same - and 0 under age field.

mahesh

Jon Marshall · ‎03-31-2010

Mahesh

The age time in the output is the amount of time the entry has been cached without being renewed. Because there is constant traffic from your router to the next-hop the cache will forever be being renewed so that is why you see it as 0 most of the time.

Jon

View solution in original post

Jon Marshall · ‎03-31-2010

Mahesh

- under the age field simply means the address is local to the router ie. it is configured on the router.

Jon

mahesh18 · ‎03-31-2010

Hi Jon

thanks for reply yes that is correct

so what does 0 mean under age field?

mahesh

Jon Marshall · ‎03-31-2010

Mahesh

The age time in the output is the amount of time the entry has been cached without being renewed. Because there is constant traffic from your router to the next-hop the cache will forever be being renewed so that is why you see it as 0 most of the time.

Jon

mahesh18 · ‎03-31-2010

H Jon

Many thanks again for your explanation

regards

mahesh