Some web servers can't access the internet because of router

[guest]

Situation: Some web servers can't access the internet and the Internet visitors can't access some web sites host by those servers. The Cisco firewall ASA can ping the servers' IP addresses and the server can ping the ASA.

Troubleshooting: We found the Cisco router has this command line: arp 64.x.x.x 001b.d454.c724 ARPA. We don't know why they setup this way, but remove it, then those servers work fine.