I would like to confirm an equipment config we will implement utilizing some specific Cisco equipment and a new high-speed WAN circuit. Currently we have a 20mbps and 6mpbs circuit coming into our environment (Ethernet handoffs) that we have front ended with a 3825 for BGP support. Our BGP is strictly route advertising and not evaluating every packet. We are upgrading to a new 100MBPS fiber circuit (Ethernet handoff) to the same 3825 and removing the 6mbps circuit, so we will BGP the 100/20 mbps circuits. The 3825 will be able to handle the higher speeds?
It is my understanding since we are simply monitoring routes (a single default route) to offer BGP support the 3825 can support speeds up to 180mbps?
an anti spoofing ACL like ACL 100 applied to the internet interface means a performance penalty for sure but I'm not able to provide exact numbers: I cannot say if performance is reduced by 50% rather then 20%.
Performance tests with traffic generators should be done.
I did tests on ACL load some years ago on C7500 and as you can imagine the cpu load increases with the number of lines of the ACL and the position where traffic matches.
In other words most traffic will be legitimate and so it will match last line of the antispoofing ACL.
BGP load is lightweight in your case if you receive only default routes.
On the other hand an anti-spoofing ACL is a need in current Internet.
Another point is that to forward 90 Mbps the cpu will be 100%.
If you really want to be able to have a full rate 100 Mbps internet pipe you may consider to use a different device for the FE handoff:
if you have a multilayer switch like C3750E I would consider it.
Hope to help