Some time ago our company decided to go to DHCP IP addressing rather than using static. We also decided to stop using hubs and instead use 3COM switches. We thought this would help us out but now there are problems and I cannot tell if it is a 3COM switch issue or a DHCP issue.
Several computers cannot under any circumstances, access the Internet using DHCP. DHCP assigns automatically the IP address, DNS, and default gateway. All check out ok. They can browse the network, but when they try to get out to the Internet, they cannot. Others work just fine.
Here is another strange thing. Whatever IP addressed which was assigned to that workstation is the ONLY one that can be used, otherwise, access to the Internet is denied. For instance my workstation always used a lease for 192.168.4.210 - One day, DHCP assigned it 211 and it didn't work. I had to manually reserve 210 so it would work.
My question is, where is the blockage coming from? My switch database says there are 198 mac addresses in it. I know that is not true. There are at most, 40 PC's connected at any one time. I thought the aging process was supposed to remove a man address that didnt send any packets after 30 minutes, but apparently it is not doing that. Would the 3COM switch not allow the packets to pass through if it is receiving it from a mac address/IP address it does not recognize? Or is something happening on the DHCP side?
Any help would be greatly appreciated. If I have't been clear enough, let me know and I'll see if I can fill in some more details.
Several computers cannot under any circumstances, access the Internet using DHCP. DHCP assigns automatically the IP address, DNS, and default gateway. All check out ok. They can browse the network, but when they try to get out to the Internet, they cannot. Others work just fine.
Here is another strange thing. Whatever IP addressed which was assigned to that workstation is the ONLY one that can be used, otherwise, access to the Internet is denied. For instance my workstation always used a lease for 192.168.4.210 - One day, DHCP assigned it 211 and it didn't work. I had to manually reserve 210 so it would work.
My question is, where is the blockage coming from? My switch database says there are 198 mac addresses in it. I know that is not true. There are at most, 40 PC's connected at any one time. I thought the aging process was supposed to remove a man address that didnt send any packets after 30 minutes, but apparently it is not doing that. Would the 3COM switch not allow the packets to pass through if it is receiving it from a mac address/IP address it does not recognize? Or is something happening on the DHCP side?
Any help would be greatly appreciated. If I have't been clear enough, let me know and I'll see if I can fill in some more details.