Connecting a router to a switch

[myers]

In my office I have 8 PC's that i want to connect to a 1901 switch, should the cables be patch, crossover, or straight through? Second, I want to connect that switch to a 2501 router. Which ports should I use on the switch and router? I don't see any uplink on the router. Third, which cables should I use to connect the switch to the router?

 

[hexn]

ok bud,

from pcs to switch - straight-through

from switch to router - straight-through

If you want to use the uplink port on the switch to plug into the router, then you will need a crossover.

 

[myers]

Im using the TX (25)port on my 1924 switch to connect to a 2501 router. So I use a straight through cable. But there is no port on the router that will accept 100mpbs port. These are the ports that are on the router:
Console
Auxillary
ISDN
db-15 aui port

 

[hexn]

You purchase a thing called a "transciever" that you plug into the AUI port. This converts the AUI port to a 10Mb RJ45 Ethernet Port.

I am assuming your switch will do 10Mbps. If it ONLY does 100Mbps, then you are plum out of luck.

That is your only option.

 

[NewbieGirl]

Going back to the straight and x-over cable. How do u know when to use a straight vs a x-over? I always thought that if you are conneting from NIC to NIC then it would be a x-over. Also, wit his switch is running 100mbps couln't he just buy a 100mbps transciever?
Thanks,
Danielle

 

[hexn]

I dont believe this is such a thing as a 100Mbps AUI Transceiver.

From NIC to NIC is a crossover. From NIC to hub/switch is a straight-through. The router has a nic on it, not a hub port. So from router to switch is a straight-through.

 

[SkyHawkTech]

well if you haven't got it going by now... just plug all the pc's into the switch with straight through cables.. the router can be plugged into 100T port straight through or one of the 10T ports with a crossover cable.. also.. 10 mbs is just fine for internet access with the 2501 but if your 8 pc's are wanting to share info then at least find a 100T switch or hub to connect all the pc's into and your router... (10T on a lan is very very old).. ;-)

~Rick

 

[msir]

When you use two different devices (PC-switch....) you must use strigh cable but when you use two same devices (PC-PC, switch-switch) you should use x-over

 

[NewbieGirl]

Maja..there's no exception to that rule?
switch to router=straight, hub to hub=cross, pc to router=straight Thanks,
Danielle

 

[adam108]

To understand whether to use a straight or cross, I determine where in the TCP/IP Model each device fits. Devices which coexist in the same layer of the model need a crossover. Devices which do not exist within the same layer need a straight cable.

Thus, since Hubs/Bridges/Switches all exist in the Physical layer of the TCP/IP model, you must use a crossover to connect them together. Routers and PC's have meaningful IP addresses (switch IP addresses are for management only) therefore they exist in the Network layer. To connect a PC to a Router, you would need a crossover.

If you are not crossing between network and physical layer devices, you need to use a crossover. If you are crossing between network and physical, you do not need a crossover.

 

[compuser2]

if u want to use 100 mbit switch port u need a 100 megabit router like the 2600 series.

 

[stoney66]

So what do you do when you connect a layer 3 switch with a layer 3 router.

 

[ChrisAC]

TCP/IP layers have nothing to do with it! It's down to DCE devices and DTE devices.

"Devices which coexist in the same layer of the model need a crossover. Devices which do not exist within the same layer need a straight cable."

A switch (layer 2) connects to a hub (layer 1) with a crossover.

Chris.
************************
Chris Andrew, CCNA
chris@iproute.co.uk
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[adam108]

Semantics, ah ah. In the OSI model switches are indeed distinguishible from hubs. However in the TCP/IP model, OSI 1 & 2 are co-located in the Physical Layer.

I do agree, Chris, that cabling really has nothing to do with either model, but I've found it easier for co-workers and myself in the early days to be able to classify hardware.

A layer 3 switch is still a switch.

 

[ChrisAC]

Okay, without getting too picky about OSI/TCP/IP layers, take a guess, cross-over or straight through? You've got a 50/50 chance of getting it right ... if it doesn't work change the cable!

You can't go far wrong using this method.

;-)

Chris.
************************
Chris Andrew, CCNA
chris@iproute.co.uk
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