my server is configured to have a public ip on one network card, and a private ip on the other network card... the server was running fine after some time... suddenly i'm unable to access my server from outside my isp network...
at first i thought it's because i recently changed my ip address, until the same thing happen to 3 other servers (that i'm in charged to) on totally different network... one is running with the same isp (same network as my previous server), one is running with different isp (not even in the same country), and the other one is running with different isp (same country)...
the conditions i checked :
from outside the server isp network:
- able to ping to the server
- traceroute to the server has no problem
- unable to access the webserver
- unable to access the ssh
- unable to access the sftp
from inside the server isp network (using public ip):
- able to ping to the server
- traceroute to the server has no problem
- able to access the webserver
- able to access the ssh
- able to access the sftp
there's no firewall set on the servers... is there anything i should check? i'm also asking to my isp as i put this question... this also happens only on occasion...