[PATCH V2 2/2] bonding support for IPv6 transmit hashing
From: John <hidden>
Date: 2012-04-18 00:37:43
--- a/Documentation/networking/bonding.txt 2012-02-08 19:21:53.000000000 -0800
+++ b/Documentation/networking/bonding.txt 2012-02-13 01:11:35.000000000 -0800@@ -753,12 +753,22 @@ protocol information to generate the hash. Uses XOR of hardware MAC addresses and IP addresses to - generate the hash. The formula is + generate the hash. The IPv4 formula is (((source IP XOR dest IP) AND 0xffff) XOR ( source MAC XOR destination MAC )) modulo slave count + The IPv6 forumla is + + iphash = + (source ip quad 2 XOR dest IP quad 2) XOR + (source ip quad 3 XOR dest IP quad 3) XOR + (source ip quad 4 XOR dest IP quad 4) + + ((iphash >> 16) XOR (iphash >> 8) XOR iphash) + modulo slave count + This algorithm will place all traffic to a particular network peer on the same slave. For non-IP traffic, the formula is the same as for the layer2 transmit
@@ -779,19 +789,30 @@ slaves, although a single connection will not span multiple slaves. - The formula for unfragmented TCP and UDP packets is + The formula for unfragmented IPv4 TCP and UDP packets is ((source port XOR dest port) XOR ((source IP XOR dest IP) AND 0xffff) modulo slave count - For fragmented TCP or UDP packets and all other IP - protocol traffic, the source and destination port + The formula for unfragmented IPv6 TCP and UDP packets is + + iphash = + (source ip quad 2 XOR dest IP quad 2) XOR + (source ip quad 3 XOR dest IP quad 3) XOR + (source ip quad 4 XOR dest IP quad 4) + + ((source port XOR dest port) XOR + (iphash >> 16) XOR (iphash >> 8) XOR iphash) + modulo slave count + + For fragmented TCP or UDP packets and all other IPv4 and + IPv6 protocol traffic, the source and destination port information is omitted. For non-IP traffic, the formula is the same as for the layer2 transmit hash policy. - This policy is intended to mimic the behavior of + The IPv4 policy is intended to mimic the behavior of certain switches, notably Cisco switches with PFC2 as well as some Foundry and IBM products.