wifi bridges and ip conflicts

[VJ]

Have any of you guys ever configured wifi bridges?

I have had MANY issues with Linksys WET54g bridges. The network is supposed to contain 1 router, 2 said bridges and (sometimes) my laptop.

The procedure to configure a bridge is:
1. connect it to the router via cable
2. browse to 192.168.1.226
3. configure the wifi settings
4. disconnect from cable, connect to bridged device

I have configured the bridges to use DHCP, and tests show that they are given a new ip address (192.168.1.101 and 192.168.1.102). However, as soon as one of them is connected via a cable to the router (for configuration purposes) while the other one is in the network (wireless or also via cable), I'm getting IP address conflicts. Each bridge seperately can be configured (and they do not share an IP address), and both can play together nicely on wireless. But it is a pain when I have to reconfigure a bridge (which has been the case a number of times) as I need to unplug the other one.

Where does that ip address conflict come from? Is it the router remembering things and giving an alert on based on different MAC addresses? Or is it my Windows? How can I solve it? (I tried "ipconfig /flushdns" but to no avail)

I'm wondering if it might not be a better option to give the bridges a fixed IP address (somewhere outside the DHCP range); I have a feeling this might be easier for configuration purposes.

Any advices? Hints? Suggestions?



Jörg

[MultimediaMan]

You definitely want all of your network infrastructure (Routers, Managed Switches, Bridges, APs) using either hardcoded IP Addresses or using DHCP IP reservations. Ditto for Servers and Appliance type-devices, too. Why? You want to be hitting a fixed target. It makes troubleshooting and configuration much simpler if you know well ahead of time what your IPs are.

Unless you are running a DNS server on your internal network, flushing DNS cache will get you nowhere.

[VJ]

Thanks!
I'll reconfigure the bridges next weekend (they are at my parents place).

I also talked to our system administrator. He said to delete the entry for the first bridge in the ARP table of the Windows machine used to configre the bridges. The first bridge factory defaults to 192.168.1.226; after giving it a new IP address (via webbrowser), I should clear the ARP for this address before connecting the second bridge (which also has the default addres 192.168.1.226). This ought to resolve the "ip conflict" windows complains about.


Jörg

[VJ]

One more thing... The network will have:
- router
- bridge which connects a pc
- bridge which connects a tv (allows for media streaming)
- laptop

I'll assign the bridges a fixed ip address, and use dhcp for the laptop.
I'm also in doubt about the pc though: it acts as a media server for the TV... I'll have to check if I can enter a server name in the TV, or if it only allows for an IP address entry (in which case fixed is the way to go).
EDIT: The manual for the TV states that DHCP is preferred for the addresses for both TV and PC (media server). So I'll go that route for those devices.


Jörg

[MultimediaMan]

If I were you:

I'd set my Router's DHCP IP address range from 192.168.1.101 to 192.168.1.253 (Gives you 152 "DHCP Managed" Addresses this is close to stock: I prefer using the 192.168.0.254 address as a "hail Mary" in case something is truly screwed on the network.)

Make sure the firmware on the Bridges is up-to-date. I would plug into each of the Bridges Directly (forgetting the router for the time being) and individually assign one Bridge a static IP of 192.168.0.90, and the other Bridge 192.168.0.91, disabling DHCP on both Bridges, and saving each configuration before plugging them into the Router.

Give your TV Media Streaming device a static DHCP address on the Router's DHCP Reservation page; make it an easy-to-remember address= 192.168.0.150 or something like that.

Other than that, you should have no issues.

[VJ]

I assume you are mixing subnets 192.168.0.x and 192.168.1.x...?
I do intend to change the default subnet from 192.168.1.x to 192.168.3.x; the reason is that my laptop tends to try and get the same address on different wireless networks, which poses a problem at work (initially, it connects with its last used address, causing a IP conflict). By having different subnets, I can solve this problem (I set my own wireless network to 192.168.2.x just for this reason).

But yes. I would choose a smaller dhcp address pool (default = 192.168.1.100 - 192.168.1.149). Plugging the bridges directly to the PC is indeed an option, but as they both default to 192.168.1.226, I might still have to remove this entry from the PC's ARP table (or Windows might complain). I'll first try by plugging them one by one to the router (less hassle with IP addresses and cables), but remove the ARP entry from the Windows PC after having configured the first one.

The router is a Linksys WRT54GL, I can't find a DHCP reservation page on it.

I checked the TV manual and the software. Apparently, TV performs a broadcast on the network to find the media servers (multiple media servers can be present on a network, one can then choose from a list), as one cannot enter a name or IP address for the media server.


Jörg

[MultimediaMan]

Sorry, I meant to key in 192.168.1.244, and 192.168.1.90, and 192.168.1.91 respectively.

You would only need to plug the bridges into the wired port of a PC for initial configuration of the Bridges.

I'm shocked there is not reservation page on that Router; most Linksys Routers support this.

Instead of purging your cache, just do an ipconfig /release& ipconfig /renew from the commandline. DHCP will be configured on the bridges to start with, so at least you'll be in the door. Better yet, if you assign yourself a hardcoded IP address (192.168.1.254) you can forget about mucking about with the ARP table.

I suspect another reason you may be getting this message is that you happen to have both wired and wireless cards on your laptop. Disable the wireless card when doing this initial setup.

[VJ]

I'm shocked there is not reservation page on that Router; most Linksys Routers support this.

Well, I have a Linksys WRT54GC and it lacks the DHCP reservation; now this WRT54GL of my parents also lacks it. Am I perhaps overlooking the page (could you verify in the manual I posted above)?

DHCP will be configured on the bridges to start with, so at least you'll be in the door. Better yet, if you assign yourself a hardcoded IP address (192.168.1.254) you can forget about mucking about with the ARP table.

No, the bridges' default address is 192.168.1.226, not DHCP. Hence the conflict in the ARP table.

I suspect another reason you may be getting this message is that you happen to have both wired and wireless cards on your laptop. Disable the wireless card when doing this initial setup.

I used the desktop PC from my parents, which only uses one network interface (a second one is disconnected from any network and not used).


Jörg