From 92abf75033d2677a684c623d60f093b130c4b38f Mon Sep 17 00:00:00 2001 From: Jianhua Xie Date: Thu, 17 Jul 2014 14:16:26 +0800 Subject: [PATCH] bonding: update bonding.txt for Layer2 hash factors Document the Layer 2 hash factors with packet type ID field. CC: Jay Vosburgh CC: Veaceslav Falico CC: Andy Gospodarek CC: David S. Miller CC: Pan Jiafei Signed-off-by: Jianhua Xie Signed-off-by: David S. Miller --- Documentation/networking/bonding.txt | 31 ++++++++++++++-------------- 1 file changed, 16 insertions(+), 15 deletions(-) diff --git a/Documentation/networking/bonding.txt b/Documentation/networking/bonding.txt index 9c723ecd0025..eeb5b2e97bed 100644 --- a/Documentation/networking/bonding.txt +++ b/Documentation/networking/bonding.txt @@ -542,10 +542,10 @@ mode XOR policy: Transmit based on the selected transmit hash policy. The default policy is a simple [(source - MAC address XOR'd with destination MAC address) modulo - slave count]. Alternate transmit policies may be - selected via the xmit_hash_policy option, described - below. + MAC address XOR'd with destination MAC address XOR + packet type ID) modulo slave count]. Alternate transmit + policies may be selected via the xmit_hash_policy option, + described below. This mode provides load balancing and fault tolerance. @@ -801,10 +801,11 @@ xmit_hash_policy layer2 - Uses XOR of hardware MAC addresses to generate the - hash. The formula is + Uses XOR of hardware MAC addresses and packet type ID + field to generate the hash. The formula is - (source MAC XOR destination MAC) modulo slave count + hash = source MAC XOR destination MAC XOR packet type ID + slave number = hash modulo slave count This algorithm will place all traffic to a particular network peer on the same slave. @@ -819,7 +820,7 @@ xmit_hash_policy Uses XOR of hardware MAC addresses and IP addresses to generate the hash. The formula is - hash = source MAC XOR destination MAC + hash = source MAC XOR destination MAC XOR packet type ID hash = hash XOR source IP XOR destination IP hash = hash XOR (hash RSHIFT 16) hash = hash XOR (hash RSHIFT 8) @@ -2301,13 +2302,13 @@ broadcast: Like active-backup, there is not much advantage to this bandwidth. Additionally, the linux bonding 802.3ad implementation - distributes traffic by peer (using an XOR of MAC addresses), - so in a "gatewayed" configuration, all outgoing traffic will - generally use the same device. Incoming traffic may also end - up on a single device, but that is dependent upon the - balancing policy of the peer's 8023.ad implementation. In a - "local" configuration, traffic will be distributed across the - devices in the bond. + distributes traffic by peer (using an XOR of MAC addresses + and packet type ID), so in a "gatewayed" configuration, all + outgoing traffic will generally use the same device. Incoming + traffic may also end up on a single device, but that is + dependent upon the balancing policy of the peer's 8023.ad + implementation. In a "local" configuration, traffic will be + distributed across the devices in the bond. Finally, the 802.3ad mode mandates the use of the MII monitor, therefore, the ARP monitor is not available in this mode.