Proxy arp is a feature that is recommended to disable if you have a router facing interne.
and better to enable only on interfaces that are working in an internal LAN.
#ip proxy-arp
[will make the router advertise itself "mac address" as the
mac address of the destination needed instead of the real device]
Disable
ARP proxy globally is
# ip arp proxy disable and under interface is
#no ip
proxy-arp
Ok, so now what is the proxy ARP?
It’s a feature
that is enabled by default on Routers that enabled the router to direct the
traffic for
network that doesn’t have Reach-ability to
destination when the router interface have the route to it.
If you disable the Proxy-ARP on interface the router 1 will not be able
to reach router6 loop-back interface, the reason is it won't be able to get L2 mac address Of the destination, [the reason is using ip route to exit interface of
the router instead of IP address of next hop]
if you enable debug for it #debug IP packets you
will see encapsulation error,
which means router failed to build Layer 2 frame
The solution
is to
- hard-code the ARP and mac address for the destination then it will be reachable.
- Or enable the proxy ARPon interface
- Use IP route to next hop address instead of pointing to the exit interface
