I am trying to setup a PIX 501 firewall that sits behind a DSL modem on a home network that consists of three PC's. I have the PIX setup as a dhcp server for the inside interface. It seems to be assigning addresses ok to the PC's. I can ping an outside ip from within the PIX, but I cannot access any web pages via a browser from any of the computers on the LAN. I can see the dns info, so that looks like its ok. when I try to connect to the internet, the firewall logs the following "710005: UDP request discardedfrom10.0.1.104/137toinside:10.255.255.255/netbios-ns" and thats it.
I found that if I manually specify a set of dns servers using the "dhcpd dns" command, that I can browse the internet. still not sure why the dhcp wasn't getting this automatically. I could ping any valid outside address from the FW all along, and I could enter the ip address of a site in the browser instead of the hostname and it would work fine. would like to know why the dns wasn't getting through automatically, if anyone has any thoughts? at least it is working though. thanks
Please forgive this post since I am not an expert or have any expierience in the PIX 501. Three weeks ago, I purchased a PIX 501 and tried to install it with two desktop and one laptop computer to safely share the Internet. Thru much help with the ARS networking board and this particular forum, everything works super. The pix shares 3 computers and also one access point for wireless laptop. The only differences between yours and my config are listed below. If you have already found the answer, that's great. I am only saying below works for me. Good Luck, it was very stressful until the final instruction made it work.
--------------> domain-name ciscopix.com
fixup protocol ftp 21
pager lines 24
--------------> icmp permit any unreachable outside
In this case, the PIX is both a DHCP client and a DHCP server. As a DHCP client, it was recieving DNS info from your ISP and could probably resolve things just fine. Your inside computers, however, are relying on THEIR DHCP server (in this case, the PIX) to provide them with all the info they need. So yes, "dhcpd dns" must be set in order for your client computers to get all of their info.
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