06-13-2003 06:14 AM - edited 03-02-2019 08:07 AM
have a 3745 with the 36-port Ethernet module in it to provide inline power and connectivity for IP phones. I am having trouble getting everything to play nicely, specifically inter-VLAN routing and DHCP on the 3745.
If I setup the router with sub-interfaces (int fa0/0.55, etc.) like you would do on an external router, I can get inter-VLAN routing between the router, a switch and another router in my test network, but my IPphones and clients can't get DHCP from the switch module or communicate at all.
If I setup the router with VLAN interfaces (int VLAN 55, etc.) like you would do on a switch or RSM, I can get inter-VLAN routing on the devices (IP phones, laptop) connected to the 36 port module, but I can't ping the switch, router, etc. (anything not connected to the 36-port module).
And obviously you can't do both (sub-interfaces and VLAN interfaces).
I have a setup already with a 3745 where we're not using the 36-port module, and the phones plug directly into a 3524-PWR-XL switch and we trunk between the switch (using int VLAN 55, etc.) and the router (sub-interfaces), and everything works fine, since the logic is on two seperate devices. But when I go to put everything on the 3745, I can only get one or the other.
I found a forum article mentioning an upgrade to the IOS. I am currently running c3745-is-mz.122-8.T5.bin. I downloaded c3745-js-mz.122-13.T.bin but when I go to install it is says that there's not enough room on the device. Shouldn't is prompt me to erase then continue?
Any ideas on this??
06-13-2003 12:51 PM
After a lot of research, I figured it out...
Can't do sub-interfaces (Layer 3) on FA0/0 or FA0/1 with the ESW, it needs layer 2, and you can't trunk on FA0/0 or FA0/1. So you need to use "Int VLAN YY" instead of sub-interfaces to get your clients on the ESW to be able to do inter-VLAN routing.
This still leaves one issue......how do I trunk the VLANs to an upstream device (mine is a 2950) if FA0/0 or FA0/1 don't do trunking (Layer 2)??? Plug a cross-over from your uplink on upstream switch to a port on the ESW. That one took me a long time to figure out, but it's Friday.
Chad
06-13-2003 12:52 PM
One more thing...there is a bug with the IOS not asking me to erase the flash file before loading another one......you need to delete and squeeze to get ti to work.
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide