IT Employment·20,070 discussions

w2k cisco router config problem

Locked

I tried to swap an smc barricade router with a new cisco soho91 router last night.
I have 7 peer-to-peer machines…3 xppro, 3 w2k, 1 w98se.
I have a cable modem with internet access shared by all.
When the wap was complete (2 minutes) and the new router was registered with the isp, I released/renewed the ip’s succesfully, but could only get to the internet with the xp and 98 machines.
I tried every conceivable config combo I could think of on the router and on the w2k machines.
I tried static ip’s on both, combos of static/dynamic, changed subnets…etc.
I finally called Cisco and spent 3 hours on the phone without a successful resolution.
I could never ping beyond the router, but could ping the router.
The tech at Cisco was telnetted in and could ping in.
He finally gave up and told me to reload windows 2k on each machine.
These are production machines in my customers office…not an option.
I put the SMC ack in, reregistered and all machines worked fine.
Any ideas?
Thanks, Gordon

Topic

Some solutions

In reply to w2k cisco router config problem

Ok looks at though it could be some service that is disabled within win2k machines? The type of ports win 2k machine r trying to access?

service?

In reply to Some solutions

If a service was disabled, then why would it work on the MC router?
Also, I just took 1 machine to my shop and hooked it up to my network…same isp.
I use a Symantec VPN100 firewall/router.
It works fine on that router.
So far SMC and Symantec OK, Cisco Not.
Gordon

Start w/ the basics

In reply to w2k cisco router config problem

If all of the PCs are using IP, then if the router is configured correctly, IP is an all or nothing deal.

You left out a lot of pertinent details,
1)Are you NATing?
2)Are you using a switch or hub?
3)What service on the Internet were you trying to use, and were you trying to access the same services on every machine?
4)Is there a mix of DHCP and static IP during testing? Is it possible that DHCP (on the router LAN port)may have tried to assign addresses that were statically assigned to other machines?

Before you go too nuts, debug IP by setting up the router with only the basics, and then connect (and debug) machines one at a time. Use ALL DHCP or ALL STATIC. Small network, I suggest static for simplicity, as you probably have an entire class C network available to you.

Good luck and open this in Q&A next time!

basics

In reply to Start w/ the basics

I am using the router as DHCP.
I am NATing.
Simply web connection on the Internet, all machines the same.
No mix of IP’s, all dhcp…although I tried static IP’s too and mixing.
Router is set to basic (default) setup no firewall.
I have tried connecting 1 machine (w2k) at a time and most of my testing with 1 xp, 1 w2k.
I have a 3com SS2 10 speed 24port.
I tried w/o the 3com, directly into the router.

Easiest way…..

In reply to basics

1) Disable the DHCP service on the router
(you only have a few machines)

2) Make a list of machine names

3) Make another list of your IP address’.
IE.
192.168.1.1
192.168.1.2
etc

4) Combine the 2 lists.
(I usually will make my network devices (rtr’s, switches in the 1-9 range. My Servers 10-20 range, user IP’s 100-199 range, user’s with no inet access 200-254) ***No 2 machines can have the same IP!!!!

5) Then manually set your router’s internal IP.
(That becomes your gateway IP) usually this is .1

6) Manually set every system IP according to your list.

7) Make it easy on your self and set the subnet mask of all machines, inlcuding the internal IP of the router to 255.255.255.0

8) Make sure each machine is pointing to the correct valid DNS server.

If you still can not surf the net after all of that, then something else is really wrong. And typically that would be on the router/nat side with some sort of #of Hosts restriction.

easy way

In reply to Easiest way…..

I tried that…sorry.

Router

In reply to w2k cisco router config problem

I’m assuming you are using the router as the DHCP server.

You have a number of conflicting symptoms here:

The fact that the WinXP and and Win98 machines have Internet access suggests that the problem lies with the WWin2K computers.

The fact that the Win2K machines work on the other routers would lead to one of two conclusions:
1. There is some sort of misconfiguration on the Win2K machines and the other routers are less “finicky” about the misconfiguration than the Cisco.
2. There is some sort of misconfiguration on the Cisco.

So let’s check a couple of things (if you haven’t already):

What happens if JUST the Win2K computers are connected?

Are there any differences in configuration of the Local Area Connection (as far as clients, services, or protocols) between the Win2K machines and the others? In particular, is the QoS Packet Scheduler installed? I have had instances where this service has caused problems.

When you perform the IP release/renew operation on the Win2K machines, do the new IP addresses belong to the same IP address range as the other computers?

Could the router be misconfigured to allow only a certain range of IPs outbound access?

Hope this gives you some things to think about.

thinking about

In reply to Router

Just w2k…same problem.
Just 1 w2k…same problem.
The only difference in lan config that I have not check…but will now… is QoS Packet Scheduler.
I know it is installed on the xp machines.
All machines are in the same subnet, no conflict, not outside the range…both in the default 10.10.10.1 (2) – 100 on the Cisco and in the range 192.168.10.1 (2) – 49 when I changed the Cisco default…I thought the 10’s might be conflicting with the ISP.
I tried static and automatic assignment.
Both were in the range.
I will check QoS however…thanks.

That brings up…

In reply to thinking about

…an initeresting question, what IP range is the ISP actually using? It’s possible they might be using the 10’s like you said, or the 192 might show up somewhere also. Might want to think about using 172.16.1.0 as your network .1 for router, .2-.254 for DHCP.

this brings up answer

In reply to That brings up…

They only use 10’s if you are not registered customer…otherwise 12’s
I did try a different ip manually, both on the router and the machines.
Cisco suggests I get a sniffer and see where the packets are going.

Hold on….

In reply to thinking about

Are you saying that you have 2 different subnets running……?

On your router you have 2 ip’s, Your WAN ip, the one assigned to you by your ISP. This should be a public routable IP. Unless your ISP is doing some sort of weird static NAT routing.

The 2nd IP should be one from one of the pvt address’ ranges: 10.x.x.x/8, 172.16.x.x/12, or 192.168.x.x/16.

All of your internal machines would *HAVE* to be from the same network as your internal IP of your router.

So if your internal IP of your router is
192.168.10.1/24 (255.255.255.0)

The all of your IP’s must be 192.168.10.2-254/255.255.255.0
And your default gateway on those machines must be
192.168.10.1

If it is ~anything~ else other then that sort of scenario, it will not work.

Hold on..reply

In reply to Hold on….

No, just 1 ip.
wan – 12…
If you are not a registered customer with isp I have seen a 10… come up and you are sent to their error page requiring your immediate registration.
That’s why I tried a manual ip setting in the router and on the machines.
Still no go.

So your on AT&T?

In reply to Hold on..reply

A 12.x.x.x IP is in the AT&T range.

A 10.x.x.x address is a non-routable private address. The 12.x.x.x address is a routable address.

Your Router, if it *only* has 1 IP address, and that IP is a 12.x.x.x IP. Then you are not doing NAT.

Why do I say that? Because you need 2 IP’s and 2 interfaces on the router to do NAT. 1 IP is the Wan public address. And the internal address is your pvt IP (192.168.10.1). That interface must connect to a internal switch/hub or firewall(which in turn connects to a switch/hub).
And your systems connect to the switch/hub.

If you followed my advice in the previous post, and it did not work. Then there is a configuration error.

The easiest thing for you to do, is to go to each machine. Verify the IP, subnet mask and gateway.

The gateway has to be the pvt internal address of the router. Not the public external WAN address. They do not know how to route to the public address. Even if they are physically connected to the device.

Next ping the pvt ip of the router (aka gateway ip) from each machine. If each machine receives 4 replies, then they can talk to the router. If they can all talk to their gateway, then they need to ping the external interface (public wan IP).

If they can talk to the public address then they should be able to surf the net, assuming that they have a valid DNS server IP address assigned to them.

If though they can not talk to the internal IP of the gateway, then the IP and subnet mask on the client machine is wrong.

IP is extremely simple, and in that same token extremely unforgiving.

Cisco IOS Version

In reply to Hold on..reply

From what I can gather, when you set your external interface for DHCP. The ISP hands out an ip address from the 10.0.0.0/8 network. I have had this exact same problem with a 2514 router.

The problem boiled down to the IOS version. I upgraded my IOS, then I received a valid DHCP address, instead of an address from the 10.0.0.0/8.

I believe that the IOS version required was 12.2(22) or higher, running the IP Plus features.

HTH,

Brian

DHCP

In reply to Router

I was kind of thinking something similar to that:

Is there a rogue DHCP service running on one of the 2K machines? What about Group Policies? Clear them on the 2K machines if you have them in place, and rebuild & test them one by one.

dhcp

In reply to DHCP

I’ll have to check.

csco switch , waps connect wirelessly but not network connection or interne

In reply to w2k cisco router config problem

I have a small topology, with no routers at all.

We use the 172.16.2.x range not the normal 192.168.x.x

We have DSL speakeasy to a sonic firewall the firewall goes to a main cisco switch. the switch then goes to seperate departments. Netgear switches.

on one of the netgear switches we have tried to make our network wireless. We have our own DHCP and static ip’s DHCP range 205-224

static ips all over the place work great. if you plug a laptop in the wall the dhcp server nt 4 service on a pc we use, gives the laptop an ip address just fine.

So it sounds like plug the wireless WAP right in right?

WRONG, i plug in, chan ge my ip address to configure to be on the ip address of 172.16.2.x

We config the Linksys WAP54G’s to the tech support level 2 standards. we log out.

All our wireless laptops see the WAP and connect with excellent signal strength.

But no network computers pingable, no releas renew with ipconfig.

No internet.

And ontop of that cant even ping these WAP’s. Its a good wap, we have 3.

Earlier we tried belkin wireless outers, they worked for a few hours, then the fimware cant be pinged.

Anyone know whats up???

[Author]

Replies