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Cisco router to hub

T

TiziteLayinLow

Senior member
i have a cisco rouer provided by time warner business class. on the back of the router is 4 rj45 ports.. they are all labeled by "X".. and the hub has an uplink port.. can i just use one of the X ports on the router and put that to the uplink port.. with straight threw cable? and also would a crossover cable work from one of the X ports to one of the hub ports(not uplink?)..

also does there need to be any setting changes in the cisco router to enable this? will the DHCP just send the IPs to the other computers?

thanks guys
 
not exactly sure.. does it vary from model to model as far as the actual wiring diagram? basically i have 1 computer hooked directly to the router and it gets the IP DHCP and it works perfect.. and i have a hub with 4 computers on it. im taking the hub into the router.. ive done this with linksys routers and stuff but never cisco.. i didnt know if there was any difference or not.

thanks
 
The "X" would be indicating that those are MDI-X ports - the same as on your hub.

The uplink port would be an "MDI" port (no "X").

You need to use a straight-through cable for MDI-to-MDIx, and a crossover cable from MDI-to-MDI or MDIx-to-MDIx.

Just to be clear, you should NEVER, EVER, EVER connect a port to another port on the same switch, uplink or not. I am assuming that what you meant on the first post was whether to use a straight-through or a crossover between the hub and the router (which has a four port switch built-in: the four port switch is connected to a single port on the router-side of the box .... the "WAN" port is the other port of the router).

Good Luck

Scott
 
ok thanks! you just confirmed what i had thought.

i will use a straight threw from the X port on the router to the uplink port on the hub.
 
OK I just got around to getting this done.. i tried a straight through cable from the X port on the cisco router, to a port on the hub.. the hub has 1-8 rj45 ports.. none are labeled uplink, theres a switch on teh hub to select "normal" or "uplink".. its set on normal, and i kind of want to leave that in that mode.. so i would change the wire to a crossover cable?

also.. on teh cisco router is there a setting anywhere in it that i need to turn on another port on the back or anything? just wanting to make sure.

the cisco model is: uBR900

and im wondering if the router isnt setup very secure because they get tons of popups, i figured it would have some type of NAT based firewall built in teh router like my linksys at home.

any advice would be greatly appreciated guys, thanks
 
Originally posted by: ScottMac
Just to be clear, you should NEVER, EVER, EVER connect a port to another port on the same switch, uplink or not.
Click to expand...

Why not? I assume damage to the switch...
 
basically, yes, your cisco router is using NAT. If your Cisco Router is using NAT, all you have to do is point your stations to the router.

If you want their IP address to be static...modify their TCP/IP configurations manually at each station and point their gateway to the cisco ubr900 (192.168.1.1) and their DNS to 24.95.80.45 & 24.95.80..41.

I don't know why you gave your stations a different subnet mask (or how they got that unique subnet mask)...but there is no need to create subnets for this network. The subnet mask for each PC should be 255.255.255.0 for a standard class C network. Generally (correct me if im wrong people)...u want the same subnet mask on all communicating devices. Your 172.16.x.x addresses are actually class B internal addresses. Make them Class C by using the 192.168.1.x scheme ure used to seeing on ure linksys.

I dont know the use of your "Internet PC", but I suggest you connect your server directly to the router and let your stations come off the hub. What that allows is all the stations to share the connection on one port and your server can utilize the bandwidth off of its own port. I suggest the same for the "Internet PC" if you're using it to serve to your network.

If this was too confusing, I can draw u a diagram...let me know
 
TechPro: On many switches, connecting one port to another can create a loop that will generate a broadcast storm.

The new stuff may have some logic to prevent such things: I haven't tried it in a while ..... but it used to be a guaranteed network stoppage.

Switches will propagate a broadcast/multicast out all ports (except the originating port) ... when you feed a broadcast out port X, and feed it back into port Y, the broadcast has a new source, so it will also be propagated ... and the loop continues.

Spanning Tree was designed to prevent these kind of loops in bridged networks (a switch is just a fancy multiport bridge) .... but most unmanaged / consumer-grade switches don't have Spanning Tree.

A hub will behave differently ... basically any traffic will generate a collision and every attached host will end up never putting any clear traffic on the wire.

FWIW

Scott
 
ok well the gateway that is on the network now is 172.16.12.49 .. im not sure but im thinking that is the server IP address.. because theres software on the workstations that talk to the server and it might have to be setup that way in order for the data to send/receive correctly. (this is a pharmacy that uses certain software). i was thinking maybe change the gateway on teh server to reflect back to the cisco router.. and make the subnet on all the machines the same 255.255.255.0, then im assuming that i would have to bridge the 2 connections, or something to get the internet passed through the server onto the hub?

can i do that - have a gateway to 1 machine, then that machine has a gateway back to the router?

thanks for the posts guys
 
Originally posted by: ScottMac
TechPro: On many switches, connecting one port to another can create a loop that will generate a broadcast storm.

The new stuff may have some logic to prevent such things: I haven't tried it in a while ..... but it used to be a guaranteed network stoppage.

Switches will propagate a broadcast/multicast out all ports (except the originating port) ... when you feed a broadcast out port X, and feed it back into port Y, the broadcast has a new source, so it will also be propagated ... and the loop continues.

Spanning Tree was designed to prevent these kind of loops in bridged networks (a switch is just a fancy multiport bridge) .... but most unmanaged / consumer-grade switches don't have Spanning Tree.

A hub will behave differently ... basically any traffic will generate a collision and every attached host will end up never putting any clear traffic on the wire.

FWIW

Scott
Click to expand...

Thanks Scott! I appreciate the answer.
 
First of all, NAT uses private IP addresses. You won't be able to connect your station's to the internet without either allowing them to use DHCP or statically configuring them with Class C Private IP addresses (192.168.0.1 - 192.168.255.254) and a consistent subnet mask.

On most Cisco routers, every port can be its own network. For your router, I don't believe this is the case. I believe your Cisco router is just like any other linksys router; the connections on the back are only available for multiple computers. Now, I could be wrong.

Nonetheless, private IP addresses are not routeable.

But honestly, you're going to make this small network all too complicated. Unless you have to specify IP addresses in the pharmacy software...this new setup will work. I?ll post in next reply
 
You need to configure your server manually. This address should stay static. All other PCs should be able to use DHCP just fine. Make sure you configure your server's IP first so your Cisco router won't give its IP address away (preferable you make it something like 192.168.1.253 so it won't ever conflict).

If the pharmacy client software need to know the specific IP address of the server...than dig into it and make sure it knows the server's IP.

If the server needs to know the client IP addresses, than configure the stations manually. Check out your best practice layout at www.krisstech.com/tizitelayinlow .
 
kfranc9 - big help, ill mess with the software and see if it can be configured this way. it gets a little more complicated because they have their server hooked up with satellite internet connection for insurance claims, which i want to run through the RR as well to save $130/mo.. but if their server side software has that setting an option ill be ok.. the only problem there is going to be.. im assuming that server needs to have certain external ports open to talk to whatever it talks to, and ill have to set that up on the cisco router unless all ports are open, which is going to be an even bigger problem, and i dont know how to change settings on cisco routers.. but ill learn

Also- that software you have on your server for the topology that you gave me, can you send me that? looks to be very helpful in large setups.

Once again, thanks a lot for your help!
 
Its called Microsoft Visio 2003. It costs a few hundred dollars though. Keep me up to date...what operating systems are these computers running?
 
-ok i have the cisco router (X) going to port 8 on the hub, and the uplink switch is turned on. the light on the router and hub both light up. i have one of the stations set to all DHCP, and static DNS. for some reason ipconfig /renew will not renew, they are NT machines. any ideas?
 
test connectivity from the workstation to the dhcp server via ping. Of course try rebooting (and/or upgrading the OS).
 
upgrading the OS is out of the question due to the fact that they are leased computers from a pharmacuetical company and have very strict rules/policies from the DEA and very high up.

i didnt think i could ping anything without an IP address?

..im going to try switching the cable to a crossover and turning the uplink switch to normal, do you think that will make a big difference?

thanks
 
Are there any other PCs that are connecting to the DHCP server? If so, you may be able to isolate the problem to the single workstation. Try ping the local loopback (172.0.0.1) This lets you know if the TCP/IP stack of the workstation is working correctly. If it works, you know its not the NIC.

Please, let me know:
Is it just this 1 workstation?
Your current network setup
Your TCP/IP settings on the workstation?
ipconfig results
 
i switched the straight-threw cable to a crossover and turned the uplink off and the router dhcp worked to the workstations on the hub, so everything is good, its not exactly the perfect setup but for right now its good. thanks for your help.
 
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