why does my BGP processor occupy large memory ?

[cm1231_cisco]

i have two routers(7507) .

when i use the command which is "show process memory | include BGP" on both router.

router #2 have more larger BGP table than #1, but router #1 occupy more larger processor memory.

Router #1 have two external neighbors and one ibgp with router #2.

Router #2 have three external neighbors(each one is same AS number)and one ibgp with router #1.

such as router #2,

if the bgp is dual homing with same ISP, does it more less use processor memory for BGP router processor?

thanks

[wdrootz]

The BGP memory use in Cisco IOS is affected by many variables, some of which are number of prefixes and paths, prefix lengths, load sharing, BGP attributes, BGP policies, software and hardware. You can use the 'show ip bgp summary' command to view the memory consumed by each of these factors. I think since router2 is multi-homing to the same ISP, the path length and

attributes should mostly be the same for prefix received from each neighbor and this could result in optimizing memory usage.

Also, if you are using inbound soft-reconfiguration, more memory will be consumed to retain routes that are filtered. The BGP routes installed in the IP routing table and CEF table are also considered as memory consumed by the BGP process. You can use the 'show ip route summary' and 'show ip cef summary' commands to view this information and find out the memory consumption of the BGP process.