FastEthernet3 as WAN port? possible? Vlan?

Aug 29, 2008 4 Replies

Hi,



Can I use a FastEthernet port from my Cisco 876 as a second WAN port?



I want to add a second ISP to my Cisco 876.



---->>> Cable-internet wich uses DHCP client to one of the Ethernet ports.



(The 876 has one ADSL over ISDN port, and one ISDN BRI port, and 4 ethernet ports)



I tried the following but I did not work :(



Ethernet cable from Cablemodem plugged to FastEthernet 3.



Link comes up, but Vlan 2 is unable to obtain a DHCP IP adress. Is the DHCP broadcast correctly redirected to FastEthernet3 ?



I have set it up as follows:



interface FastEthernet3 switchport access vlan 2 mac-address 0050.bfb7.772c ! interface Vlan2 ip dhcp client client-id FastEthernet3 ip dhcp client hostname Telenet ip address dhcp no ip redirects


Greetings, Steven


I'm not sure if it can be used as a second -WAN- port, but if I recall correctly, any 876 with software made in the last several years can use one of the ethernet ports as distinct interface. I do not recall if it was the first or last port of the block of them, definitely not one of the middle ones.

"WAN" port tends to imply things about clocks and distance you can drive the signal and so-on. The port is usable as a seperate security zone, so it can be "outside" for translation purposes, and these days that is often enough rather than requiring that it have the baggage associated with the word "WAN".

Try associating the address with the FastEthernet3 instead of with the VLAN. e.g., imagine that you had switchport trunk instead of access, then the DHCP packet would be wrapped inside 802.1Q headers and thus wouldn't work. Let the interface get an IP address but make it an outside interface and have it do address translation with respect to your inside IP addresses.

Hi,

It's no problem, the best way is to use a interface bvi , and connect this to your vlan.

Walter & Woni,

Thanks for the replies!

Greetings, Steven.

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