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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: maximum active vlans in a crisco 6509
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 2000-06-20-23:01:45 Roeland Meyer (E-mail): > > Bob Biver: Tuesday, June 20, 2000 7:28 PM > > the docs say max 250, is this informational or a limit of > > spanning tree? > > If I recall correctly, that's also real close to the maximum > number of physical connections to the chasis, with all modules > installed. Personally, I've never run anywhere near that number. > I don't think it is useful to have less than 2 members in a vlan. > You would also be surpassing the bandwidth limitations of that > chasis, even if all the connections were 100baseTX. For many uses, I think you certainly have a clear and reasonable point. But while I don't know what the original poster had in mind, I can fantasize a use for thousands of vlans, even on a switch that doesn't have thousands of distinct ports. And without necessarily exceeding available bandwidth. Lessee, suppose I were designing something like an internet-access-for-hotel-rooms, or thereabouts. Or suppose otherwise I had thousands of users who didn't trust each other, at all, who I didn't want to have sniffing each other's traffic, who were just wanting to share access to an internet connection, itself less than 100BaseT, maybe even much less. One way I could fantasize doing it would be to assign a separate VLAN to each port of as many different switches, interconnected with 802.1Q or ISL, as it took to provide ports to every room. Run one 802.1Q line into the one router in this picture, say a Linux box using iproute2 for traffic shaping. Ok, so maybe 6509s would be way overkill for this application, no way you need that kind of backplane bandwidth. But as circumstances emerge where you want to have a fully-routed network (next step up the protocol ladder from a fully-switched network --- each host gets its own dedicated router port) I can anticipate settings where VLANs might get abused in a most remarkable way. - -Bennett -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.0 (GNU/Linux) Comment: For info see http://www.gnupg.org iD8DBQE5UDpTL6KAps40sTYRAkSXAJ9zRIAdsIp1xjdS2Vl56WjTeNdmdgCghySl Z+zy1YE6u1OW3RopArzAkDg= =gFAm -----END PGP SIGNATURE-----
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