Losing Internet Access
Posted on 2008-10-10
I am at one of my remote offices and they have a problem with losing Internet access for most of the staff.
When the office opens up, the first people to connect to the Internet have access all day, the rest do not gain access. I have yet to determine the exact number of lucky users, but it may only be 10 or so of the 80 users. These 10 users have email, messenger, etc. Some of the staff are granted access to MS Messenger, but most of the users have no access at all.
Details concerning the site are as follows. There are two E1's (Mexico) coming into a Cisco 1700 router. The 1700 then connects to a Cisco PIX 501. We have a HP Proliant DL380 server running Win 2K3. It has 4 CPUs and 2 Gigs of ram right now. The server is a file server, provides DNS and Wins, and also DHCP. There is about 70 users at any given time, all running Win XP Pro. Utilization is low on the server and it is only using about 400 Megs of memory. If I reboot the firewall, those running messenger normally get the connection since Messenger will keep trying to connect if the Internet goes down.
There are a few more details that I have observed:
The whole site has complete access to the local network. No local access is lost. The whole site can still access the file server and the network printers, so I dont think it is a switch issue. I can go to any machine and ping the firewall, the file server etc. Basic TCP/IP connectivity is still there.
This site connects to another site via a VPN. The other side has a PIX 515E and the VPN link does not go down. Here is the weird part. If I have Internet access, I also have full access to the resources at the other side of the VPN. I can access terminal services to any servers, and my own personal PC via Remote Desktop. If I dont have access, I can still ping devices on the other side of the VPN, but I cannot access the servers via Terminal Services or my PC via remote desktop. I also cannot connect to the Exchange Server Funny thing is that I can access to a PC via pcAnywhere on the other side.
We have a MFP printer here (HP 4345) that has the ability to send email via an SMTP server at the other side of a VPN link. If you come in first thing in the morning, you can send email out on the printer. Once people start logging in, the printer loses connection to the SMTP server, and will not connect for the rest of the day. We have another MFP printer local to the SMTP server and it works fine and never has a problem. No matter how I try, I cannot get this printer to connect. So after 6, when the office has cleared out, the printer will then have access again and is able to send email no problem.
Is this a DNS issue or a network traffic issue, I am not sure. If I do not have Internet access, I also cannot perform a Nslookup. It says Cant find server name for the address 192.168.3.10: Non-existent domain. Machines with Internet access run Nslookup just fine. I have tried to change to a DNS server at the other side, and even public DNS servers. Still no help. I cannot access the Internet.
I can use some direction. This office has grown from about 30 people to 80 over the past two years. I was going to replace the PIX 501 with a 515E, but the Firewall failed, and I am awaiting a replacement. In the meantime, any ideas. By the way, it is quite now and I have full run of the network. No access problems at all.
This office has a VPN link to my HQ office, and the VPN stays live. These affected users still have