Here are a collection of commonly asked questions that arise from time to time on the linux-tr mailing list. If your question isn't answered here or elsewhere in this document, feel free to ask away on the mailing list.
A: Certain dhcp servers and clients do not work properly with token ring drivers. This is especially true with the 2.4 kernels. During the development of the 2.3.x series of kernels the internal type for token ring was changed to accomodate multicast support over token ring. The solution is to upgrade your dhcp client/server to a version that supports token ring and/or the latest kernel versions.
A: Firstly, double check that your adapter/driver support setting the LAA, and that you've supplied a valid LAA. Also, most drivers will only allow this to be set before the adapter is opened onto the ring. Again, this is related to the change in the internal type for token ring in the 2.4 kernels. A patch is available from the web site for nettools that fixes this and allows the LAA to be set.
A: The token ring source routing code in the kernel uses the spanning tree algorithm. Contact your network administrator to enable this protocol on the bridges.
A: The simply answer in no. Briding network topologies in software is incredibly complicated and while it is possibly, nobody has written the code to do it. If you must bridge there are several manufacturers that produce hardware bridges (most notably Cisco).
A: A cheap linux box with a token ring and ethernet adapter makes an excellent router. There is no difference between setting up a token ring/ethernet router and an ethernet/ethernet router. You can do masquerading (NAT) and filtering on the router as per usual. For more details see the Netfilter howto.