nanog mailing list archives
Re: IPv6 network boundaries vs. IPv4
From: Peter Dambier <peter () peter-dambier de>
Date: Sun, 26 Aug 2007 11:06:21 +0200
John Osmon wrote:
Is anyone out there setting up routing boundaries differently for IPv4 and IPv6? I'm setting up a network where it seems to make sense to route IPv4, while bridging IPv6 -- but I can be talked out of it rather easily. Years ago, I worked on a academic network where we had a mix of IPX, DECnet, Appletalk, and IP(v4). Not all of the routers actually routed each protocol -- DECnet wasn't routable, and I recall some routers that routed IPX, while bridging IP... This all made sense at the time -- there were IPX networks that neededto be split, while IP didn't need to be. DECnet was... DECnet -- and Appletalk was chatty, but useful. I keep hearing the mantra in my head of: "I want my routers to route, and my switches to switch." I agree wholeheartedly if there is only one protocol -- but with the mix of IPv4 and IPv6, are there any folksdoing things differently? With a new protocol in the mix are the lessons of the last 10 (or so) years not as clear-cut?
Hi John, I remember old DECNET, DDCMP, IPX and NetBios days. I used to have a couple of 19.2 kilobaud async lines, 2 arcnets and an ethernet (thinwire technology but on RG13U cables, almost yellow wire and UHF connectors - PL-259 like CB-radio). DDCMP could route, IPX could and NetBios was riding on either IPX or DDCMP so it did not matter. Later the DDCMP async was replaced with a lots of switches and repeaters. Whe used to have a backbone (yellow cable) connecting two VAXes and a repeater that was feeding some 8 thinwires. Half of the thinwires were feeding DECNET Terminalservers and PCs the other half were IPX with a single one Netware server and lots of PCs. In its best times the network was seeing some 1000 hosts. Everything was running 10 MBit ethernet. there were 9 segments and no routers. I have seen you could put some 30 NetBios PCs into a single segment or more than 200 DECNET hosts if they were connected via switches and thinwire transceivers. Today without thinwire or yellow cable and with switches that can do 1 Gbit between switches and 100 Mbit to devices you should be able to keep some 1000 hosts within a single switched network. NAT-routers seem to have a limit of some 250 hosts within a single 255.255.255.0 network. I dont know if those boxes really can do 250 or if their MAC address tables break even earlier. I have seen those boxes missbehave when a bad ethernet adapter randomly changed its MAC address. There are quite some link local things in IPv6 so it makes a lot of sense to keep them within a single network - beside that nasty /64 habit that suggests forget radvd and automatic addresses but have an IPv4 address of the 192.168... variety and use 6to4 adressing for your local network. I was running my own network, 4 IPv4 networks and 3 IPv6 networks without routers, only switches :) the 6to4 trick helped me survive but now I dont know if the IPv6 boxes were really seeing each other other simply using 6to4 routes :) Kind regards Peter and Karin -- Peter and Karin Dambier Cesidian Root - Radice Cesidiana Rimbacher Strasse 16 D-69509 Moerlenbach-Bonsweiher +49(6209)795-816 (Telekom) +49(6252)750-308 (VoIP: sipgate.de) mail: peter () peter-dambier de mail: peter () echnaton arl.pirates http://iason.site.voila.fr/ https://sourceforge.net/projects/iason/ http://www.cesidianroot.com/
Current thread:
- IPv6 network boundaries vs. IPv4 John Osmon (Aug 25)
- Re: IPv6 network boundaries vs. IPv4 Peter Dambier (Aug 26)
- DECNet Good Old Days (spun from ...network boundaries...) James R. Cutler (Aug 26)
- Re: IPv6 network boundaries vs. IPv4 Kevin Oberman (Aug 26)
- Re: IPv6 network boundaries vs. IPv4 Jason LeBlanc (Aug 27)
- Re: IPv6 network boundaries vs. IPv4 John Osmon (Aug 27)
- Re: IPv6 network boundaries vs. IPv4 Jason LeBlanc (Aug 27)
- Re: IPv6 network boundaries vs. IPv4 Iljitsch van Beijnum (Aug 27)
- Re: IPv6 network boundaries vs. IPv4 Valdis . Kletnieks (Aug 27)
- <Possible follow-ups>
- RE: IPv6 network boundaries vs. IPv4 John van Oppen (Aug 27)
- Any MSN/Live Mail Admin Contacts? Raymond L. Corbin (Aug 27)
- Re: Any MSN/Live Mail Admin Contacts? Martin Hannigan (Aug 27)
- Any MSN/Live Mail Admin Contacts? Raymond L. Corbin (Aug 27)
- Re: IPv6 network boundaries vs. IPv4 Peter Dambier (Aug 26)