I've been having problem with dns lookup that have gotten rather acute today. My mailq is usually empty, but this morning I had 40 entries which are taking about 3 hours to get queued. They have the annotation: host name lookup failure. I also have about 500 sendmail processes running and I normally have about 40. All this is telling me sendmail is having problems connecting to servers and/or resolving hostnames.
Also, I have tried pinging various hosts (such as yahoo.com, experts-exchange.com) and the pings timeout with no data. I've tried traceroute yahoo.com and I get: traceroute: unknown host yahoo.com. I've tried pinging IP addresses (ping 126.96.36.199) and it is timing out.
I suspect a problem with my DNSs, but that wouldn't explain why I can't ping an IP.
This is being a big problem. I'm running Linux 2.4.29. I'm not running named, but I have nameservers configured in resolv.conf. How do I go about figuring out my problem?