Connection issue between Cisco 515 Pix and Cisco 1841 router

[kwitham]

Hi,

I am having a problem getting a Cisco Pix 515 communicating to a Cisco 1841. I am currently studying for CCNA so forgive me if it's obvious to the rest of you where the problem lies.

The client currently has an ISDN service which is being moved over to a 2MB E1 connection.

I have configured the 1841 router with G.703 WIC according to the information given to me by the ISP. I have configured the 1841 to have the same internal IP as the ISDN Cisco 800 series router, hoping for a simple swap over. The Pix 515 sits behind the ISDN at present and will be behind the 1841 when it is active.

Once I unplug the 800 series ISDN router and plug the 1841 into the pix, I cannot get any response what so ever. I have tried changing the ethernet connection speeds between the pix and 1841 hoping it would be as simple as that without success. Can't get ping responses from either end but I can when the ISDN service is plugged in. Both ISDN and E1 link are supplied by the same ISP, Telstra Australia and the fixed IP's are able to move over to the E1 service.

I have not touched the pix in any way. A seperate company configured the router a couple of years ago.

I have included the configurations of the existing ISDN, Pix and the 1841 for you to review. Any advise/solutions would be greatly appreciated.

Thanks in Advance,

[paddyxdoyle · Accepted solution]

Hi,

The outside interface on your PIX is configured as 10BaseT which would be fine when using the original 800 series ISDN router.

Now with your new 1841, the interface that the PIX connects to is Fast Ethernet so you need to change your outside interface on the PIX to the same

If you want to use auto negotiation between the PIX and router then the command to do this on the PIX is

interface ethernet0 auto

I recommend using hard coded settings between the PIX and router and the command to do this on this PIX is

interface ethernet0 100full

You will also need to change your router as:

interface FastEthernet0/0

speed 100

duplex full

If you can't configure the PIX as you mentioned an external company did it, then i guess you could change your Fast Ethernet interface to "speed 10", "duplex half".

This won't create a bottleneck as you only have a 2 MB connection to your ISP

Everything else looks good, don't worry about asking questions on the forum, this is what its for.

HTH

Paddy

[kwitham]

Hi Paddy,

Thank you for your assistance. I have managed to get the router and pix talking to eachother at 10 Mbps Half Duplex. This will enable the pix to continue working with the ISDN router until the client is ready to swap over to the 2MB service.

Thanks again,

Keith.