Cisco 2950-Cable Question

[Bob Boklewski]

I have an issue here with cabling, not sure what to do.  We are being handed off ethernet from our isp, it is a business only broadband connection and wherever the demarc is there is the ISP'S switch and the extension from the dmarc to our suite is a straight through cable (must be).  What I did was put in a 2950 switch before our firewall so I can hand off an external ip to another router that will connect to this 2950.  The problem is I used a straight through cable from this ISP's jack in our suite to our 2950 (Doesn't support auto-mdix) and the connection didn't come up.  However, I used a crossover and the connection came up.  The thing is, I don't know if this will be reliable, because basically it is straight thru cable from the ISP's switch to the port in our suite and then I am going crossover from there.  I have never tried mix and matching cables like this because usually I have an ISP's router right in my suite. Does anybody have any idea here if this is a bad situation even though it is working?  Maybe it is working because the ISP's switch does support auto-mdix, just don't know if it is a good idea.

Let me know,

Thanks!

[Reza Sharifi]

Completely common and normal.  There is no issue what that connectivity. The older switches don't support auto-mdix and so in order to connect one switch to another you have to use a crossover cable and that is what you did.

You are good to go.

HTH

[Bob Boklewski]

Right, but usually it is crossover from one switch right to the other.  Here it is ISP's switch straight through to a port in our suite then crossover to our switch.  Just don't know if that is a good idea mixing cable types like that.

[Reza Sharifi]

It doesn't really matter.  The cable has to get crossed some where.  Now, you can go directly from one switch to another using a cross over cable or go straight to the wall jack and then cross to the other switch.

HTH

[Bob Boklewski]

So even though it isn't crossed to ISP's switch it is fine to cross to my switch?  Probably because their switch supports auto-mdix right, so it doesn't matter?

[Reza Sharifi · Accepted solution]

That is correct.  You just need to cross it on one side.

HTH

[Bob Boklewski]

Thanks, this helps, now I don't have to buy a switch that supports auto-mdix, just a long crossover.

[Reza Sharifi]

Correct.

Please rate and mark the post as answered so others can benefit from it.

Thanks,