Basic Switch Router Conversation

Daniel333

Wednesday's project

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I figured this should be simple enough. Get a Router, a switch and a workstation to all be able to ping eachother. They should probably be on the same subnet, as no real routing is being done.

Router2503A

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Switch1900A

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iMac104A

Router2503A
E0 - 10.1.0.1 /16

Switch1900A
Ip - 10.1.0.2 /16
Default Gate: 10.1.0.1

iMac104A
E0 - 10.1.0.3/16
Default Gate: 10.1.0.1


I can see the Router and Switches from eachother using CDP, but I cannot get them to ping. CDP has ruled out a cabling problem. And I can normally get routers talking without a problem, so I don't think I have messed up on the configuration of the router.

So that leaves the Switch. So how does the IP address on the switch play out on the switch? It's not applied to any specific port, so it's just for management I am assuming? Even still, I don't think there is any sort of routing protocol between the switch and router I need to set (I even applied RIP to the subnet just to be sure)

As always, thanks in advance, you guys rock. I only hope someday, I'll be at a point where I can give a little back to this site...

remyforbes777

How is the computer and the router plugged into the same port?

james_

IP Addressing scheme looks OK. Have you run a "no shut" on routers e0 interface? Ports should be up by default on the switch, but no so the router as I remember.

georgemc

First, you won't normally want a normal host on your network to be able to ping your switch, but for lab/training purposes this is a good way to learn how things work.

I'm assuming that your host machine is able to ping the gateway(router). Let me know if I'm mistaken.

I'm not very familiar with the 1900 series but if you were to place the switchports that the host and router are plugged into in the same vlan as the switches management VLAN(I'd guess this would be vlan1, you'd want to check) it should work.

On the switch, be sure to set the ip default-gateway to the address on the router port.

If you were using a router that support vlans, then your switch and you host would normally be placed in separate vlans/subnets.

malcybood

georgemc wrote:

First, you won't normally want a normal host on your network to be able to ping your switch, but for lab/training purposes this is a good way to learn how things work.

why not? what about remote management and testing connectivity? We have icmp enabled on all of our switches or do you mean only administrator host machines should be able to ping the switch?

Daniel,

All you should need to do to get each to ping each other or any other device on any other subnet (provided the rest of your network is working correctly) is:

Router#int fa0
ip address 10.1.0.1 255.255.0.0
no shut

Switch
switch#int vlan 1
ip address 10.1.0.2 255.255.0.0
no shut
exit
switch#ip default-gateway 10.1.0.1 255.255.0.0 (only needed if you want access to or from switch to another subnet i.e. 10.2.0.0. If it's on the same subnet a switches ip default gateway is optional for what you are trying to do but it's good practice to put it in anyway then apply security in access lists to the switch/router to prevent unwanted networks)

Host
ip address - 10.1.0.3
SM - 255.255.0.0
Gateway - 10.1.0.1

This should certainly let you ping between devices on this segment.

If this doesn't work when trying to ping to and from the host, then check your firewall settings on your laptop. Sometimes Macafee and Norton are setup only to allow 192.168 networks by default as these are the most commonly used by home routers i.e. Netgear, Belkin etc

Malc

georgemc

malcyblood wrote:

why not? what about remote management and testing connectivity? We have icmp enabled on all of our switches or do you mean only administrator host machines should be able to ping the switch?

Yes, that's exactly what I mean. Normally only certain "network management" machines will be allowed to have connectivity to your management vlan (VLAN1)

malcyblood wrote:

All you should need to do to get each to ping each other or any other device on any other subnet (provided the rest of your network is working correctly) is:

Router#int fa0
ip address 10.1.0.1 255.255.0.0
no shut

Switch
switch#int vlan 1
ip address 10.1.0.2 255.255.0.0
no shut
exit
switch#ip default-gateway 10.1.0.1 255.255.0.0 (only needed if you want access to or from switch to another subnet i.e. 10.2.0.0. If it's on the same subnet a switches ip default gateway is optional for what you are trying to do but it's good practice to put it in anyway then apply security in access lists to the switch/router to prevent unwanted networks)

I think you're making an assumption here that the switchports that the router and host are plugged into are in VLAN1. If they're NOT, then he will not be able to ping to or from the switch.

Georgemc

malcybood

georgemc wrote:

I think you're making an assumption here that the switchports that the router and host are plugged into are in VLAN1. If they're NOT, then he will not be able to ping to or from the switch.

Georgemc

I'm making the assumption based on the config that Daniel originally provided and the fact that he doesn't mention there there are any other VLANs configured, therefore the solution I suggested would work.

Do you have any other VLANs configured Daniel?

Cheers

Malc

Daniel333

As of right now, I am not dealing VLANs, so everything by default is working on VLAN1.

Sorry, very new to all this. So I guess I should have written it like this,

Router2503A

---

Switch1900A

---

iMac104A

Router2503A
E0 - 10.1.0.1 /16 (tranceiver to to Switch1900A's e0/1)

Switch1900A
Using administrative VLAN1.
Ip - 10.1.0.2 /16
Default Gate: 10.1.0.1

iMac104A
E0 - 10.1.0.3/16 (plugged into Switch1900A's e0/2)
Default Gate: 10.1.0.1

So anyhow, I am going to take another crack at. I think maybe I didn't bring up the VLAN1. I was assuming that it was in no shut by default as the when I had two Workstations plugged in they could communicate. Not sure what else it could be.

malcybood

Daniel333 wrote:

As of right now, I am not dealing VLANs, so everything by default is working on VLAN1.

Sorry, very new to all this. So I guess I should have written it like this,

Router2503A

---

Switch1900A

---

iMac104A

Router2503A
E0 - 10.1.0.1 /16 (tranceiver to to Switch1900A's e0/1)

Switch1900A
Using administrative VLAN1.
Ip - 10.1.0.2 /16
Default Gate: 10.1.0.1

iMac104A
E0 - 10.1.0.3/16 (plugged into Switch1900A's e0/2)
Default Gate: 10.1.0.1

So anyhow, I am going to take another crack at. I think maybe I didn't bring up the VLAN1. I was assuming that it was in no shut by default as the when I had two Workstations plugged in they could communicate. Not sure what else it could be.

I missed the fact you were using a 1900. You should just have to configure the ip address and gateway on a 1900 by doing

switch#conf t
switch(config)ip address 10.1.0.2 255.255.0.0
switch(config)ip default-gateway 10.1.0.1

this is according to Cisco's website and Todd Lammle's Sybex guide. I've never really used 1900's as they're not in the CCNA objectives and I've got 2950's. You should maybe think about trying to get your hands on a 2950

Let us know how you get on

Daniel333

I have the 1900 series and three 2500 series routers. I didn't exactly know what to buy when I got started, so I got one of those CiscoKits that advertised "everything you need..." (not quite everything as it turns out) Anyhow, I am still learning a lot, and most the concepts are the same anyway.

In about a month I might have the money to get the 2950 and a 2600 series router so I can do VLANS and trunking on it. But for now, I am trying to get the most out what I have.

Weird thing is my Cisco books are supposed to have the Netsim "lite" which is suppose to allow me to run certain labs. But when I try, pretty much anything with VLANs, it says I need to upgrade to the full version. Weird because the book has labs, that are supposed to work in the "lite" version. *shrug* Better to do the real thing.

Alright thanks for the help, I'll go play with this and see what I can do. I'll keep you guys posted.

thanks!

Daniel333

Update -

Switch can ping router
Switch can ping workstation
Switch cannot ping itself
Router can ping self
Router can ping workstation
Router can ping switch

Workstation can ping router
Workstation can ping itself
Workstaion can ping switch

georgemc

Glad to hear it's working out. It always seems to be the simplest explanation for things.

Daniel333

I am still wondering why it can't ping itself. Bah, I'll leave that until next Wednesday that's when I actually get enough free time to mess with my computers. I think I'll just try and focus on the memorization part of the CCNA-Intro exam for the rest of the night.

thanks everyone!