How to create A record on DNS server

Kunle Ajeigbe · ‎09-23-2010

How do i create an A record on the DNS server (windows server 2008) that would resolve into two ip addresses: PUB & SUB ip addresses respectivly, to enable EM redundancy in Cisco Unified Communications Manager 6.1.

Right now when the PUB failover to the SUB the EM does not work. the Phone services as well as the global directory does not work. the CUCM is fully integrated to LDAP.

Cisco recomends using an SLB but right now i am trying to use the DNS option. what i need now is how to create the A record on the DNS that would resolve into the two ip address of the PUB and SUB.

Joseph Martini · ‎09-23-2010

You can do this but your results won't be quite as expected. I've played around with this and you'll see that the request for when you press the services button will go to server A, then when you click on the EM service your request will go to server B, then the login back to server A even though you started the login session with server B and back and forth, then with the authentication information, etc. Also DNS doesn't know about the state of your servers. If a server is down you'll still have issues if the name resolves to the down IP address. As far as I've seen DNS will always round robin with multiple records for the same name (unless you use an SRV record).

Kunle Ajeigbe · ‎09-23-2010

thanks joemar,

i think there should be a way around this limitation, although Cisco recomends using an SLB for this.

Regards