The MPLS-OPS Archive[Date Prev][Date Next][Thread Prev][Thread Next] [Date Index][Thread Index][Author Index][Subject Index] RE: Tunnels in multiple OSPF areas
main difference is : -first approach I mentionned is available today in commercial tools, and can even by developped through scripting layer, or by operators themselves. It's basically building the path off-line (no time constraint), and translating it into CLI command sent to the router afterwards. Like provisioning tools available today. Result will be rather static routers, and route changes always trigerred by the operator. Implementation can be dedicated software tool, or extension to existing ones or OSS. -second approach is more dynamic. it's transparent to the operator, requires extention on the routers, and would allow dynamic path recomputing trigered on the router by timer or autobandwidth like behaviors. This can't be made easily available today. Implementation will be new software or hardware box. -----Original Message----- From: Eric Osborne [mailto:eosborne@cisco.com] Sent: mercredi 12 novembre 2003 16:41 To: Sebastien.Spas@alcatel.be Cc: Eric Osborne; Christopher Young; Kurien Joseph; mpls-ops@mplsrc.com Subject: Re: [MPLS-OPS]: Tunnels in multiple OSPF areas On Wed, Nov 12, 2003 at 03:39:06PM +0100, Sebastien.Spas@alcatel.be wrote: > thanks. > > another alternative could be to rely on network management tools to compute > the inter-area paths (net mgt tool can get global topology view through > direct discovery or OSS database), and provision the LSPs with explicit > paths (using verbatim). Sure. > > I also read some papers about "route server" approach. There, a hardware or > software box will know the whole topology, maintain the gloval TE db, and > implement routnig algorithms for LSPs (SPF, CSPF, or a specific one with > another objective like load balancing). > When provisioning a new LSP, the router will contact the route server to get > the LSP path (instead of running his internal CSPF relying on the local TE > db), using a specific protocol. > The route server should be nearly as fast as local CSPF implementations, and > should allow to use dynamic paths on the router config. > How is this fundamentally different from the first approach you describe? It seems to me to be the same thing, except for the speed of reaction to changes. > Do you know anything about the state of this approach ? Is there any RFC, > protoype, or even commercial products implementing it ? > There's been some IETF work in this area, I think - I'll leave this answer to JP, since that's more his area than mine. eric > kr, > seb. > > -----Original Message----- > From: Eric Osborne [mailto:eosborne@cisco.com] > Sent: mercredi 12 novembre 2003 15:21 > To: Sebastien.Spas@alcatel.be > Cc: Eric Osborne; Christopher Young; Kurien Joseph; mpls-ops@mplsrc.com > Subject: Re: [MPLS-OPS]: Tunnels in multiple OSPF areas > > > On Wed, Nov 12, 2003 at 01:00:36PM +0100, Sebastien.Spas@alcatel.be wrote: > > Hi, > > > > can't you easily setup such tunnels across several areas using an explicit > > path ? > > Yes. It makes more sense to do so using loose ERO subobject, but as > of 12.0(26)S you can also use the 'verbatim' command to force the > headend not to check the TE DB for the existence of the hops in your > path prior to signalling. > > Inter-area TE really needed two things: > 1) loose ERO (for which verbatim is a poor, but workable, > substitute) > > 2) ability on the ABR to have more than one TE DB (one for > area 0 and one for each of the other areas) > > The feature I pointed to has both of those in it. > > > > eric > > > > > kr, > > seb. > > > > -----Original Message----- > > From: Eric Osborne [mailto:eosborne@cisco.com] > > Sent: mercredi 12 novembre 2003 0:07 > > To: Christopher Young > > Cc: Kurien Joseph; mpls-ops@mplsrc.com > > Subject: Re: [MPLS-OPS]: Tunnels in multiple OSPF areas > > > > > > On Tue, Nov 11, 2003 at 03:49:16PM -0500, Christopher Young wrote: > > > Kurien, > > > > > > I don't believe that Traffic Engineering works across multiple OSPF > > > areas yet. > > > > it does, but it depends on code versions. > > I'm not sure offhand what's in 12.3 (from the error message, it looks > > like inter-area support isn't there), but it certainly works in 12.0S > > code. > > > > > http://www.cisco.com/en/US/products/sw/iosswrel/ps1612/products_feature_guid > > e09186a0080080ce5.html > > > > Introduced in 12.0(19)ST1, which I think came out around November, > > 2001. So update your competitive spreadsheet...:) > > > > > > > > eric > > > > > Thanks, > > > > > > > > > Chris Young > > > Juniper Networks > > > -----Original Message----- > > > From: Kurien Joseph [mailto:kurienjoseph@yahoo.com] > > > Sent: Tuesday, November 11, 2003 2:31 PM > > > To: mpls-ops@mplsrc.com > > > Subject: [MPLS-OPS]: Tunnels in multiple OSPF areas > > > > > > > > > > > > I have been trying to configure a tunnel across multiple OSPF area on a > > > cisco network. I have been refering to the cisco docs that talk about > > > configuration of tunnels on multiple OSPF areas. > > > > > > There was a section about configuring an Area Border router(ABR). My > > > question is if ABR a specialized piece of hardware or software patch > > > loaded ? I have an MPLS 3600 (IOS12.3) router in the border between ospf > > > areas. Its configured as follows > > > > > > router ospf 1 > > > mpls traffic-eng router-id Loopback0 > > > mpls traffic-eng area 0 > > > log-adjacency-changes > > > network 10.225.48.0 0.0.0.255 area 0 > > > network 10.225.50.0 0.0.0.255 area 0 > > > network 10.226.0.0 0.0.0.255 area 6 > > > network 10.226.1.0 0.0.0.255 area 6 > > > network 10.226.127.33 0.0.0.0 area 6 > > > network 10.224.0.0 0.31.255.255 area 0 > > > ! > > > > > > > > > Since this router is in between area 0 and 6 should I have another entry > > > as > > > > > > mpls traffic-eng area 6 > > > > > > when I do try to issue this above command, I get > > > > > > %MPLS TE already enabled, on ospf area 0 > > > > > > Does that mean this router that I am using is not capable of being a ABR > > > ? > > > > > > (Cisco Docs Step 4 says I should issue the following commands. > > > > > > Router(config-router)# mpls traffic-eng area 0 > > > > > > Router(config-router)# mpls traffic-eng area m > > > > > > ) > > > > > > Thanks for your time. > > > > > > Kurien > > > > > > > > > > > > _____ > > > > > > Do you Yahoo!? > > > Protect <http://antispam.yahoo.com/whatsnewfree> your identity with > > > Yahoo! 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