PBR-LB - Direct Server Return Load Balancing using Policy Based Routing (MEMO) 07 Feb, 2013 SAKURA Internet Research Center Senior Researcher / Naoto MATSUMOTO

1. 07 Feb, 2013
SAKURA Internet Research Center
Senior Researcher / Naoto MATSUMOTO

2. What is PBR-LB?
1) PBR-LB (Policy Based Router–Load Balancing) is forcusing Server Scale-Out Tech.
- Breaking L2DSR(Layer 2 Direct Server Return) Limitation.
- without NAT.
- without DSCP modify (e.g. Layer 3 Direct Server Return mechanism).
- Add Tunneling Capabiltiy.
- Do not add/modify Server kernel modules.
- using Policy Based Routing Functionality on Newest Software Router.

3. How does it works.
5) Layer 3 Direct Server Return
SERVER
eth0:10.0.0.1/32
lo:A.A.A.A/32
Internet
1) Incommig Traffic 4) Nexthop Traffic
Policy Table
SRC PORT DST ADDR NEXTHOP-TABLE
1-10,000 A.A.A.A 0.0.0.0/0 -> 10.0.0.1
10,001-20,000 A.A.A.A 0.0.0.0/0 -> 10.0.0.2
20,001-30,000 A.A.A.A 0.0.0.0/0 -> 10.0.0.3
: : :
Policy Router
(VyattaCore 6.5R1 on x86 Commodity Hardware)
2) Policy Table Lookup / 3) Rewrite L3-NextHop
*Reference: L3DSR – Overcoming Layer 2 Limitations of Direct Server Return Load Balancing. Jan Schaumann, Systems Architect (NANOG51),
VYATTA, INC. Policy Based Routing REFERENCE GUIDE. (6.5R1 v01)
SOURCE: SAKURA Internet Research Center. 02/2013 Project THORN.

4. PBR-LB Configuration.
SRC PORT DST ADDR NEXTHOP-TABLE
1-10,000 A.A.A.A 0.0.0.0/0 -> 10.0.0.1
10,001-20,000 A.A.A.A 0.0.0.0/0 -> 10.0.0.2
: : :
Policy Router
(VyattaCore 6.5R1 on x86 Commodity Hardware)
vyatta$ configuration
# set policy route SRC-PORT-SLB rule 11 destination address A.A.A.A
# set policy route SRC-PORT-SLB rule 11 protocol tcp_udp
# set policy route SRC-PORT-SLB rule 11 set table 11
# set policy route SRC-PORT-SLB rule 11 source port 1-10000
# set protocols static table 10 route 0.0.0.0/0 next-hop 10.0.0.1
# set policy route SRC-PORT-SLB rule 12 destination address A.A.A.A
# set policy route SRC-PORT-SLB rule 12 protocol tcp_udp
# set policy route SRC-PORT-SLB rule 12 set table 12
# set policy route SRC-PORT-SLB rule 12 source port 10001-20000
# set protocols static table 12 route 0.0.0.0/0 next-hop 10.0.0.2
:
# set interfaces ethernet eth0 policy route SRC-PORT-SLB
# commit
# save
*Reference: VYATTA, INC. Policy Based Routing REFERENCE GUIDE. (6.5R1 v01)

5. in more detail.
$ show version
Version: VC6.5R1
Description: Vyatta Core 6.5 R1
:
$ show policy route
$ show policy route statistics
...etc

6. Thanks for your interest.
SAKURA Internet Research Center.