Can I use a Cisco 2501 to route my cable connection?

[birthofsorrow]

Is it possible to route a cable internet connection (ethernet) with a cisco 2501?


Thanks
Mike

 

[Fuzznuts]

yes it is possible using sub interfaces 2501 only has 1 ethernet port. however you need IOS 12.1+ as only this release supports getting an ip form dhcp. personally rather that botch it.id sell the 2501 and look for a 2514 or similar that has 2 ethernet intrafces makes configuration much easier you'd be up and running in minutes.

 

[birthofsorrow]

what do youmean by sub interface? hook an AUI to ethernet adapter up?

 

[RhythmAddict]

You need two eth ports to have cable connected..ie;
Cable > Eth in router > Eth out of router > switch/hub/pc

But since a 2501 only has one available eth port, you can't do that...what you could do is either buy a router with 2 eth ports, as Fuzznuts suggested, or buy another single eth router like a 2501 or similiar (this is what i have at home)
Which looks like..
Cable > WAN router > serial connection to LAN router > LAN router > switch

The wan and lan routers are both my 250X series routers...you can connect them via the serial in the back.
Hope I answered your q.

 

[birthofsorrow]

thanks man

 

[birthofsorrow]

Say I get more than one IP address via dhcp from my ISP,, would there be a way for the cisco to obtain more than one IP address via dhcp on one interface?


Thanks
mike

 

[Fuzznuts]

Originally posted by: birthofsorrow
what do youmean by sub interface? hook an AUI to ethernet adapter up?

sub interface is like and extra vitrual interface on a real one think linux eth0 and eth0:1

you can do the same with ios i.e. ethernet 0 and ethernet 0/1

as was stated its a botch ive heard it can be done but have never done it myself though due to it not being to good an idea

 

[birthofsorrow]

Ok,thx

 

[bgroff]

Originally posted by: Fuzznuts

Originally posted by: birthofsorrow
what do youmean by sub interface? hook an AUI to ethernet adapter up?

sub interface is like and extra vitrual interface on a real one think linux eth0 and eth0:1

you can do the same with ios i.e. ethernet 0 and ethernet 0/1

as was stated its a botch ive heard it can be done but have never done it myself though due to it not being to good an idea

You can't do this on a 2500 series router. In order to use sub-interfaces, you need to have vlan trunking (802.1q or ISL). This is supported with the IP plus feature set on 2600 and better routers.

 

[ScottMac]

Not with a subinterface, but a SECONDARY command on the one-and-only Ethernet interface.

Then you have a "router on a stick" AKA "One-armed router"

Not very efficient, and anybody looking at traffic on that interface will be able to capture traffic from both IP ranges. It's not at all secure. Making it secure will also make it the slowest possible router/firewall combo on the market, at any price.

Fun to play with, an educational experience "fer sher," but don't use it for "production;" it's not even good for bragging rights.

Good Luck

Scott

 

[Fuzznuts]

Originally posted by: ScottMac
Not with a subinterface, but a SECONDARY command on the one-and-only Ethernet interface.

Then you have a "router on a stick" AKA "One-armed router"

Not very efficient, and anybody looking at traffic on that interface will be able to capture traffic from both IP ranges. It's not at all secure. Making it secure will also make it the slowest possible router/firewall combo on the market, at any price.

Fun to play with, an educational experience "fer sher," but don't use it for "production;" it's not even good for bragging rights.

Good Luck

Scott

still learning knew i was in the ballpark though

 

[bgroff]

Originally posted by: ScottMac
Not with a subinterface, but a SECONDARY command on the one-and-only Ethernet interface.

Then you have a "router on a stick" AKA "One-armed router"

Not very efficient, and anybody looking at traffic on that interface will be able to capture traffic from both IP ranges. It's not at all secure. Making it secure will also make it the slowest possible router/firewall combo on the market, at any price.

Fun to play with, an educational experience "fer sher," but don't use it for "production;" it's not even good for bragging rights.

Good Luck

Scott

Bleh, that's not router on a stick. That's a physical interface with multiple IP addresses. A real router on a stick uses vlans. If the switch its connected to is modern enough, the layer 3 decision gets cached and the switching takes place on layer 2. Therefore, speed isn't much of an issue. But a 2501 isn't capable of this... and its slow as hell! But at least you can run linux on it!

 

[RhythmAddict]

I'm pretty sure you can't have multiple IP address assigned via DHCP on the same interface on a 2500 series...Just out of curiousity, why you want to do this anyway? seems like it would confuse things...

 

[birthofsorrow]

My ISP gives me multiple IP addresses but they are obtained via dhcp.

Thanks
Mike