Re: L3 DSR
"Bruno Van Dierendonck" <[email protected]>
| Newsgroups | gmane.comp.programming.load-balancing.general |
|---|---|
| Message-ID | <[email protected]> |
In L3 DSR the trick is getting the server to respond with the vip address when responding to load balanced requests. With L2 DSR you can easily use the source MAC, but with L3 this becomes more challenging. A good way to do this is with DSCP. Assuming of course that your router does not manipulate DSCP flags. This way the receiving server can distinguish content from the load balancer vs other network traffic. This is nice if you have hundreds or thousands of servers, as you can split your broadcast domains into smaller groups. This is probably not a concern for most customers, but hey if you have this problem it's a pretty nice solution. Bruno Senior System Engineer A10 Networks _____ From: [email protected] [mailto:[email protected]] On Behalf Of Joo Yong-Seok Sent: Tuesday, March 31, 2009 10:15 AM To: Load Balancing Mailing List Subject: Re: [load balancing] L3 DSR Hello, VIP health check should be done with real-server MAC address (as a Dmac) and DIP (request packet) should not be changed since all real-servers have the loop-back interfaces. (that's DSR and return packets don't need to be forwarded back to L4) I'm not quite sure about this topology but in Alteon and other L4 case, it looks like having a n issue. ;-) Best regards, - yongseok 2009/3/30 SungLyeol Choi <[email protected]> Hello. I think those are normal DSR even though L4 is connect to L3 and has two different network. my question was Clients | | <http://192.168.10.0/24> 192.168.10.0/24, VIP : 192.168.10.100 | L2 or L3-SW ==== L4 SW | | 172.16.10.1/24 L3 SW l | <http://10.10.10.0/24> 10.10.10.0/24 Servers it means Server should be located in other network. my customer told me some vendors mentioned that. in this topology L4 should send client traffic to Server by L3 SW. thanks. Date: Mon, 30 Mar 2009 10:22:50 -0700 (PDT) From: Surya ARBY < <mailto:[email protected]> [email protected]> Subject: Re: [load balancing] L3 DSR To: Load Balancing Mailing List < <mailto:[email protected]> [email protected]> Message-ID: < <mailto:[email protected]> [email protected]> Content-Type: text/plain; charset="utf-8" Hello. I guess it protects against L2 broadcast because you can build L2 isolation by constraining? return traffic to go to the routing point of the network, thus limiting flooding, that's the only sense I take from the sentence :) Surya --- En date de?: Lun 30.3.09, Kenneth Salchow < <mailto:[email protected]> [email protected]> a ?crit?: De: Kenneth Salchow < <mailto:[email protected]> [email protected]> Objet: Re: [load balancing] L3 DSR ?: "Load Balancing Mailing List" < <mailto:[email protected]> [email protected]> Date: Lundi 30 Mars 2009, 17h59 Maybe I?m forgetting something, but I believe *all* DSR (direct server return) is L3.? L2 DSR wouldn?t be too useful unless you had one really, really big, flat, private network, would it? ? Most vendors support this type of configuration in one way or the other?but I also don?t know of any that recommend the configuration, except for very specific circumstances.? But?even in video streaming these days, there are benefits to running the traffic back through the ADC in order to manage out-bound traffic flow?and there are plenty of boxes that can handle the throughput. ? So?when you talk about ?protecting L2 Broadcast??what exactly are you trying to do and why? ? --and, if I?m being complete silly, please forgive me?it is Monday morning.? J ? KJ (Ken) Salchow, Jr.??|??Manager, Technical Marketing ? From: <mailto:[email protected]> [email protected] [mailto: <mailto:[email protected]> [email protected]] On Behalf Of SungLyeol Choi Sent: Monday, March 30, 2009 9:46 AM To: <mailto:[email protected]> [email protected] Subject: [load balancing] L3 DSR ? Hi guys. ? Have you heard about L3 DSR? which vendors support this? I heard L3 DSR could protect L2 broadcast. but I think LB should consider a lot of things to support that. ? Thanks. _______________________________________________ lb-l mailing list <mailto:[email protected]> [email protected] <http://vegan.net/mailman/listinfo/lb-l> http://vegan.net/mailman/listinfo/lb-l Searchable Archive: <http://vegan.net/lb/archive> http://vegan.net/lb/archive <http://lbdigest.com/> http://lbdigest.com Load Balancing Digest <http://lbwiki.com/> http://lbwiki.com Load Balancing Wiki -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://vegan.net/pipermail/lb-l/attachments/20090330/6b17b93c/attachment-00 01.html> http://vegan.net/pipermail/lb-l/attachments/20090330/6b17b93c/attachment-000 1.html ------------------------------ Message: 2 Date: Mon, 30 Mar 2009 10:25:39 -0700 From: Joo Yong-Seok < <mailto:[email protected]> [email protected]> Subject: Re: [load balancing] L3 DSR To: Load Balancing Mailing List < <mailto:[email protected]> [email protected]> Message-ID: < <mailto:[email protected]> [email protected]> Content-Type: text/plain; charset="iso-8859-1" I suppsoe that L2 or L3 config doesn't matter. the important thing in DSR is "returning packet" should not be forwarded to L4 and L4 should not do any processing for that. Clients | | <http://192.168.10.0/24> 192.168.10.0/24, VIP : 192.168.10.100 | L3-SW ==== L4 SW | | | <http://10.10.10.0/24> 10.10.10.0/24 Servers In this topoloty, L4 can have two interfaces for <http://192.168.10.0/24> 192.168.10.0/24 and <http://10.10.10.0/24> 10.10.10.0/24. In Servers point of view, GW should be L3-SW. Client requests will be forwarded to L3 but L3 knows the VIP location (L4) and it will forward the request via L2-fwd. L4 will do a client processing and send the packet to Servers. In this moment, DSR should be enabled and request packet's DIP is not modified. and Server will received the packet and then forward it to L3-SW since L3-SW is a gateway for servers. I suppose that this is L3 DSR and return packet will not traverse to L4. Also, L4-SW is in the same network with servers, health check by using real-mac (VIPhealth) is also working and No mac flapping. (Since L4 is doing L3 fwd + L4 processing and packet's SIP should be modified. L3-SW will not have any duplicate mac-address entry in the fdb. - Even there are same mac in fdb, if VLAN is different, there should be no issues to do a L2-fwd). I have no idea why L2 broadcast issue is there on DSR. (do you mean "mac-flapping"? - this can cause flooding in the network). Best regards, - yongseok 2009/3/30 SungLyeol Choi < <mailto:[email protected]> [email protected]> > Hi guys. > Have you heard about L3 DSR? > which vendors support this? > I heard L3 DSR could protect L2 broadcast. but I think LB should consider a > lot of things to support that. > > Thanks. > > _______________________________________________ > lb-l mailing list > <mailto:[email protected]> [email protected] > <http://vegan.net/mailman/listinfo/lb-l> http://vegan.net/mailman/listinfo/lb-l > Searchable Archive: <http://vegan.net/lb/archive> http://vegan.net/lb/archive > <http://lbdigest.com/> http://lbdigest.com Load Balancing Digest > <http://lbwiki.com/> http://lbwiki.com Load Balancing Wiki > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://vegan.net/pipermail/lb-l/attachments/20090330/87d718d9/attachment-00 01.html> http://vegan.net/pipermail/lb-l/attachments/20090330/87d718d9/attachment-000 1.html ------------------------------ Message: 3 Date: Mon, 30 Mar 2009 10:43:17 -0700 From: Joo Yong-Seok < <mailto:[email protected]> [email protected]> Subject: Re: [load balancing] L3 DSR To: Load Balancing Mailing List < <mailto:[email protected]> [email protected]> Message-ID: < <mailto:[email protected]> [email protected]> Content-Type: text/plain; charset="iso-8859-1" There is TYPO. SIP ---> SMAC. Best regards, - yongseok On Mon, Mar 30, 2009 at 10:25 AM, Joo Yong-Seok < <mailto:[email protected]> [email protected]>wrote: > I suppsoe that L2 or L3 config doesn't matter. the important thing in DSR > is "returning packet" should > not be forwarded to L4 and L4 should not do any processing for that. > > Clients > | > | <http://192.168.10.0/24> 192.168.10.0/24, VIP : 192.168.10.100 > | > L3-SW ==== L4 SW > | > | > | <http://10.10.10.0/24> 10.10.10.0/24 > Servers > > In this topoloty, L4 can have two interfaces for <http://192.168.10.0/24> 192.168.10.0/24 and > <http://10.10.10.0/24> 10.10.10.0/24. In Servers point of > view, GW should be L3-SW. Client requests will be forwarded to L3 but L3 > knows the VIP location (L4) > and it will forward the request via L2-fwd. > > L4 will do a client processing and send the packet to Servers. In this > moment, DSR should be enabled > and request packet's DIP is not modified. and Server will received the > packet and then forward it to L3-SW > since L3-SW is a gateway for servers. > > I suppose that this is L3 DSR and return packet will not traverse to L4. > > Also, L4-SW is in the same network with servers, health check by using > real-mac (VIPhealth) is also > working and No mac flapping. (Since L4 is doing L3 fwd + L4 processing and > packet's SIP should be > modified. L3-SW will not have any duplicate mac-address entry in the fdb. - > Even there are same mac > in fdb, if VLAN is different, there should be no issues to do a L2-fwd). > > I have no idea why L2 broadcast issue is there on DSR. (do you mean > "mac-flapping"? - this can cause > flooding in the network). > > Best regards, > > - yongseok > > 2009/3/30 SungLyeol Choi < <mailto:[email protected]> [email protected]> > >> Hi guys. >> Have you heard about L3 DSR? >> which vendors support this? >> I heard L3 DSR could protect L2 broadcast. but I think LB should consider >> a lot of things to support that. >> >> Thanks. >> _______________________________________________ lb-l mailing list [email protected] http://vegan.net/mailman/listinfo/lb-l Searchable Archive: http://vegan.net/lb/archive http://lbdigest.com <http://lbdigest.com/> Load Balancing Digest http://lbwiki.com <http://lbwiki.com/> Load Balancing Wiki _______________________________________________ lb-l mailing list [email protected] http://vegan.net/mailman/listinfo/lb-l Searchable Archive: http://vegan.net/lb/archive http://lbdigest.com Load Balancing Digest http://lbwiki.com Load Balancing Wiki