recently we acquired corporate ADSL connection to our company.
i configured a pc as firewall and router.
one network interface of th pc is labelled as wan and public ip was configured.
the other end has ip 172.16.16.1 and labelled as lan interface and connects to core switch.we have a dhcp server for lan purpose.
the problem started when tryiong to connect internet by directly connecting cat 5e ethernet straight cable from adsl modem to the wan interface of the pc.the firewall pc and clients cannot connect to internet.
suspecting the problem could be the cable ,it was checked with cable tester but it is perfect. even i tried with another stright cable but the same problem exists.
i alos tried with a crossed cable connecting the modem and pc directly,but no use.
amazingly the pc's can connect internet only when the adsl modem is connected to an ethernet switch and the wan interface of the pc also connected to the same switch.
so please can u figure out what actully went wrong....