Pinging over Serial Links that Have ACLs
Figure B-9 illustrates a simple network topology with two routers connected to a serial link. Note that four IP ACLs exist, named A, B, C, and D, as noted by the thick arrows in the drawing. That is, ACL A is an outbound ACL on R1’s S0/0/0, ACL B is an inbound ACL on R2’s S0/0/1, and so on.
Figure B-9 Sample Network with IP ACLs in Four Locations
First, consider the case in which host H1 pings the IP address of host H2. Assuming that H1 and H2 are in the same subnet, router R1 does not even receive the IP packet. Even if router R1 had ACLs on its G0/0 interface, R1 has no chance of filtering the packet ...
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