I have an ASA 5520 that I have used for several years as my vpn endpoint for remote users and site to site.   Using cisco vpn client on remote users,   I can ping my dns servers by ip and name,  I can ping certain server names by ip and by name but not all.   For instance.  I have forwarding zones on my dns server:   companya.com, companyb.com, companyc.com   from my remote user I can ping server.companya.com and server.companyb.com  but can not ping server.companyc.com (however I can ping server.companyc.com by ip address) so it has to be a dns issue somewhere.   Any suggestions?  thank you in advance