Agent Server Error

Hi All,
Recently we got swapped IP between two server. Server A IP is xxxx and while Server B IP is yyyy. After swap IP the situation should be like this Server A IP is yyyy while Server B IP is xxxx. We use /etc/hosts to swap the IP an restart the both server at same time. Found abnormal error keeps on pop up at Server B. The error as below

Sep 17 16:29:47 sundbs2 agent[28355]: [ID 659312 daemon.alert] syslog Sep 17 16:29:47 agent agentServer parameter (old IP) is not a valid local hostname

Is that related to SUNWsymon?
Anyone can share how to solve the above error?

Have you followed the documentation regarding IP address/hostname change in your Solaris operating system (you didn't specify which version of Solaris in the post) ?

Or you just modified some files and hoped for the best ?

Regards
Peasant.

Hi Peasant,
Sorry, Solaris 10.
My previously DBA who handled Solaris DB server informed me that sawpped the server IP is just by edit the host IP in /etc/hosts then restart the both server same time.
What I find peculiar only one server got this error while the other did not have the error.
Can advise me?