Hi, it''s posibility to make something similar to Cisco unnumber on Linux ? E. g. interface Serial0 ip unnumbered Ethernet0 I don''t want to assign to interface private IP. PSIkappa psi@atlantis.sk
On Fri, 22 Jun 2001, M.F. PSIkappa wrote:> it''s posibility to make something similar to Cisco unnumber on Linux ? > E. g. > interface Serial0 > ip unnumbered Ethernet0 > I don''t want to assign to interface private IP.If I understand the ip unnumbered command correctly it allows you to share a single IP address on multiple interfaces. This is trivial on Linux: just add the same IP address to each of the interfaces with ip addr add The routing effects I cannot correctly comment on, as I''m not sufficiently versed in IOS to fully grasp the effects of ip unnumbered Doei, Arthur. -- /\ / | arthurvl@sci.kun.nl | Work like you don''t need the money /__\ / | A friend is someone with whom | Love like you have never been hurt / \/__ | you can dare to be yourself | Dance like there''s nobody watching
On Fri, 22 Jun 2001, Arthur van Leeuwen wrote:> On Fri, 22 Jun 2001, M.F. PSIkappa wrote: > > > > it''s posibility to make something similar to Cisco unnumber on Linux ? > > E. g. > > interface Serial0 > > ip unnumbered Ethernet0 > > I don''t want to assign to interface private IP. > > If I understand the ip unnumbered command correctly it allows you to share a > single IP address on multiple interfaces. This is trivial on Linux: just add > the same IP address to each of the interfaces with ip addr add > > The routing effects I cannot correctly comment on, as I''m not sufficiently > versed in IOS to fully grasp the effects of ip unnumberedNo, it''s incorrect, unnumberd allow you to connect 2 router without IP adresses. 192.168.0.1/24 [cisco]unnumbered-----unnumberd[cisco] 192.168.2.1/24 It''s special case of point-to-point connection. In linux if I make point-to-point connection I have to assign any IP on both endpoint of connection.> Doei, Arthur.PSIkappa psi@atlantis.sk
On Fri, 22 Jun 2001, M.F. PSIkappa wrote:> On Fri, 22 Jun 2001, Arthur van Leeuwen wrote: > > > On Fri, 22 Jun 2001, M.F. PSIkappa wrote: > > > > > > > it''s posibility to make something similar to Cisco unnumber on Linux ? > > > E. g. > > > interface Serial0 > > > ip unnumbered Ethernet0 > > > I don''t want to assign to interface private IP. > > > > If I understand the ip unnumbered command correctly it allows you to share a > > single IP address on multiple interfaces. This is trivial on Linux: just add > > the same IP address to each of the interfaces with ip addr add > > > > The routing effects I cannot correctly comment on, as I''m not sufficiently > > versed in IOS to fully grasp the effects of ip unnumbered > > No, it''s incorrect, unnumberd allow you to connect 2 router without IP > adresses. > > 192.168.0.1/24 [cisco]unnumbered-----unnumberd[cisco] 192.168.2.1/24 > > It''s special case of point-to-point connection. In linux if I make > point-to-point connection I have to assign any IP on both endpoint of > connection.What is the difference with 192.168.0.1/24 [linux] 192.168.0.1 ------- 192.168.2.1 [linux] 192.168.2.1/24 if I may be so bold to ask? Yes, the routing effects may be different, and I mentioned that might be a problem, but the unnumbered thing looks like a cisco-specific hack... Doei, Arthur. -- /\ / | arthurvl@sci.kun.nl | Work like you don''t need the money /__\ / | A friend is someone with whom | Love like you have never been hurt / \/__ | you can dare to be yourself | Dance like there''s nobody watching
On Fri, 22 Jun 2001, Arthur van Leeuwen wrote:> > > > it''s posibility to make something similar to Cisco unnumber on Linux ? > > > > E. g. > > > > interface Serial0 > > > > ip unnumbered Ethernet0 > > > > I don''t want to assign to interface private IP. > > > > > > If I understand the ip unnumbered command correctly it allows you to share a > > > single IP address on multiple interfaces. This is trivial on Linux: just add > > > the same IP address to each of the interfaces with ip addr add > > > > > > The routing effects I cannot correctly comment on, as I''m not sufficiently > > > versed in IOS to fully grasp the effects of ip unnumbered > > > > No, it''s incorrect, unnumberd allow you to connect 2 router without IP > > adresses. > > > > 192.168.0.1/24 [cisco]unnumbered-----unnumberd[cisco] 192.168.2.1/24 > > > > It''s special case of point-to-point connection. In linux if I make > > point-to-point connection I have to assign any IP on both endpoint of > > connection. > > What is the difference with > > 192.168.0.1/24 [linux] 192.168.0.1 ------- 192.168.2.1 [linux] 192.168.2.1/24 > > if I may be so bold to ask? Yes, the routing effects may be different, and I > mentioned that might be a problem, but the unnumbered thing looks like a > cisco-specific hack...Difference is in traceroute. Unnumbered is invisible, if I assign IP I see it in traceroute, but I can make hack that make this connection invisible, but it''s rfc break ... Yes, it''s cisco specific hack.> Doei, Arthur.PSIkappa psi@atlantis.sk
On Fri, Jun 22, 2001 at 10:31:04AM +0200, M.F. PSIkappa wrote:> > The routing effects I cannot correctly comment on, as I''m not sufficiently > > versed in IOS to fully grasp the effects of ip unnumbered > > No, it''s incorrect, unnumberd allow you to connect 2 router without IP > adresses. > > 192.168.0.1/24 [cisco]unnumbered-----unnumberd[cisco] 192.168.2.1/24 > > It''s special case of point-to-point connection. In linux if I make > point-to-point connection I have to assign any IP on both endpoint of > connection.So, in effect, you''re changing the behaviour of your (level 3) port to a level 2 port, i.e., a switch, and add some filtering features to it, or am I missing something? In that case, you might get away by configuring the two pairs of ports as ethernet bridge ports, and only assign IP-addresses to the two outer interfaces as in the diagram above. Not sure whether all shaping and firewalling tricks will work in that case though. Anyone got a comment on that? Regards, -- Q_. Jasper Spaans <j@sp3r.net> `~\ http://jsp.ds9a.nl/ Mr /\ Tel/Fax: +31-84-8749842 Zap Move ''.sig'' for great justice!
On Fri, Jun 22, 2001 at 10:34:37AM +0200, Arthur van Leeuwen wrote:> On Fri, 22 Jun 2001, M.F. PSIkappa wrote: > > > On Fri, 22 Jun 2001, Arthur van Leeuwen wrote: > > > > > On Fri, 22 Jun 2001, M.F. PSIkappa wrote: > > > > > > > > > > it''s posibility to make something similar to Cisco unnumber on Linux ? > > > > E. g. > > > > interface Serial0 > > > > ip unnumbered Ethernet0 > > > > I don''t want to assign to interface private IP. > > > > > > If I understand the ip unnumbered command correctly it allows you to share a > > > single IP address on multiple interfaces. This is trivial on Linux: just add > > > the same IP address to each of the interfaces with ip addr add > > > > > > The routing effects I cannot correctly comment on, as I''m not sufficiently > > > versed in IOS to fully grasp the effects of ip unnumbered > > > > No, it''s incorrect, unnumberd allow you to connect 2 router without IP > > adresses. > > > > 192.168.0.1/24 [cisco]unnumbered-----unnumberd[cisco] 192.168.2.1/24 > > > > It''s special case of point-to-point connection. In linux if I make > > point-to-point connection I have to assign any IP on both endpoint of > > connection. > > What is the difference with > > 192.168.0.1/24 [linux] 192.168.0.1 ------- 192.168.2.1 [linux] 192.168.2.1/24 > > if I may be so bold to ask? Yes, the routing effects may be different, and I > mentioned that might be a problem, but the unnumbered thing looks like a > cisco-specific hack...Sorry, it doesnt look so -- as far as i know unnumbered interfaces (PtoP connections) are supported by a number of vendors. Having a possibility to create unnumbered links under Linux would be nice, imho.> > Doei, Arthur. > > -- > /\ / | arthurvl@sci.kun.nl | Work like you don''t need the money > /__\ / | A friend is someone with whom | Love like you have never been hurt > / \/__ | you can dare to be yourself | Dance like there''s nobody watching > > > _______________________________________________ > LARTC mailing list / LARTC@mailman.ds9a.nl > http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://ds9a.nl/2.4Routing/-- Dmytro O. Redchuk http://www.popnet.kiev.ua System Administrator Phone: (380).44.495.26.05 PopNet Kommunikation Kiew Fax : (380).44.495.26.02
On Fri, 22 Jun 2001, M.F. PSIkappa wrote:> On Fri, 22 Jun 2001, Arthur van Leeuwen wrote: > > > > > > it''s posibility to make something similar to Cisco unnumber on Linux ? > > > > > E. g. > > > > > interface Serial0 > > > > > ip unnumbered Ethernet0 > > > > > I don''t want to assign to interface private IP. > > > > > > > > If I understand the ip unnumbered command correctly it allows you to share a > > > > single IP address on multiple interfaces. This is trivial on Linux: just add > > > > the same IP address to each of the interfaces with ip addr add > > > > > > > > The routing effects I cannot correctly comment on, as I''m not sufficiently > > > > versed in IOS to fully grasp the effects of ip unnumbered > > > > > > No, it''s incorrect, unnumberd allow you to connect 2 router without IP > > > adresses. > > > > > > 192.168.0.1/24 [cisco]unnumbered-----unnumberd[cisco] 192.168.2.1/24 > > > > > > It''s special case of point-to-point connection. In linux if I make > > > point-to-point connection I have to assign any IP on both endpoint of > > > connection. > > > > What is the difference with > > > > 192.168.0.1/24 [linux] 192.168.0.1 ------- 192.168.2.1 [linux] 192.168.2.1/24 > > > > if I may be so bold to ask? Yes, the routing effects may be different, and I > > mentioned that might be a problem, but the unnumbered thing looks like a > > cisco-specific hack... > > Difference is in traceroute. Unnumbered is invisible, if I assign IP I see > it in traceroute, but I can make hack that make this connection invisible, > but it''s rfc break ...Ah, but iptable''s mangle module will let you play around with the TTL field of packets being forwarded through a linux box. Yes, it takes some more configuring, but the behaviour can be duplicated. And that is not considered a hack. Besides, ever heard of masquerading? That is nowhere near RFC compliance... and should theoretically be impossible, if I''m to believe Jos Vos (one of the first implementers). Doei, Arthur. -- /\ / | arthurvl@sci.kun.nl | Work like you don''t need the money /__\ / | A friend is someone with whom | Love like you have never been hurt / \/__ | you can dare to be yourself | Dance like there''s nobody watching
On Fri, 22 Jun 2001 10:55:41 +0200 (CEST), M.F. PSIkappa wrote:>> > No, it''s incorrect, unnumberd allow you to connect 2 router without IP >> > adresses. >> > >> > 192.168.0.1/24 [cisco]unnumbered-----unnumberd[cisco] 192.168.2.1/24 >> > >> > It''s special case of point-to-point connection. In linux if I make >> > point-to-point connection I have to assign any IP on both endpoint of >> > connection. >> >> What is the difference with >> >> 192.168.0.1/24 [linux] 192.168.0.1 ------- 192.168.2.1 [linux] 192.168.2.1/24 >> >> if I may be so bold to ask? Yes, the routing effects may be different, and I >> mentioned that might be a problem, but the unnumbered thing looks like a >> cisco-specific hack... > >Difference is in traceroute. Unnumbered is invisible, if I assign IP I see >it in traceroute, but I can make hack that make this connection invisible, >but it''s rfc break ...This is correct, in the workings... But I don''t think it really breaks the RFC''s... Anyways this is the diffrence: All networks prefixed with "10.0"... Numbered: ----- 10.0.1.1/24 [[[Linux Box]]] 10.0.0.100/24 -----Ethernet----- 10.0.2.1/24 [[[Linux Box]]] 10.0.0.200/24 ----- Unnumbered: ----- 10.0.1.1/24 [[[Linux Box]]] -----P to P----- [[[Linux Box]]] 10.0.0.200/24 ----- As you can see, the unnumbered is a Point to Point connection, and acts more like a "bridge"... Actually, if you want to do an Unnumbered connection with two Ethernet Interfaces, thats exactly how I would set it up... as a Bridge. Either that or use PPPoE and that should be able to do something simular.>Yes, it''s cisco specific hack.No this is not true... Alot of the Point to Point (IE: Dial-Up, ISDN) type Internet Connections use Unnumbered Connections. There are a large number of companies that support these type of connections. --Greg. ------------------------------------- Greg Varga Owner: Digital Realities http://www.digital.realities.com 604.576.2219 Lead Programmer of MUTAG http://www.bvcompuworks.com/mutag Network Administrator -------------------------------------
On Fri, Jun 22, 2001 at 09:37:29AM -0700, Greg Varga wrote:> This is correct, in the workings... But I don''t think it really breaks > the RFC''s...It has nothing to do with the RFC''s.> > Anyways this is the diffrence: > > All networks prefixed with "10.0"... > > Numbered: > ----- 10.0.1.1/24 [[[Linux Box]]] 10.0.0.100/24 -----Ethernet----- > 10.0.2.1/24 [[[Linux Box]]] 10.0.0.200/24 ----- > > Unnumbered: > ----- 10.0.1.1/24 [[[Linux Box]]] -----P to P----- [[[Linux Box]]] > 10.0.0.200/24 ----- > > As you can see, the unnumbered is a Point to Point connection, and acts > more like a "bridge"... > > Actually, if you want to do an Unnumbered connection with two Ethernet > Interfaces, thats exactly how I would set it up... as a Bridge. Either > that or use PPPoE and that should be able to do something simular. > > >Yes, it''s cisco specific hack. > > No this is not true... Alot of the Point to Point (IE: Dial-Up, ISDN) > type Internet Connections use Unnumbered Connections. There are a > large number of companies that support these type of connections.You are correct, Greg. Unnumbered interfaces are (mostly) ptp interfaces. When setting up a ptp interface you should usually use one /30 in a traditional way. Now, for a ptp connection there is only one IP entity at the other end and it doesn''t have to be one out of a /30. Any IP address will do. That''s why they usually use the loopback IP (or the IP of another interface) to identify the Unnumbered interface. I''m not sure how this can be done with linux. But I think that pppd program does not require you to waste one /30 for the link. The server side can send one /32 to the client side and announce another IP (eg, the IP of its ethernet interface) as the peer IP of the ppp link. At least this is what''s happening when you dial in to a NAS. Ramin> > --Greg.