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Diffstat (limited to 'Documentation/networking')
| -rw-r--r-- | Documentation/networking/bonding.txt | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/Documentation/networking/bonding.txt b/Documentation/networking/bonding.txt index 2c197b68baf0..334b49ef02d1 100644 --- a/Documentation/networking/bonding.txt +++ b/Documentation/networking/bonding.txt @@ -51,6 +51,7 @@ Table of Contents 3.4 Configuring Bonding Manually via Sysfs 3.5 Configuration with Interfaces Support 3.6 Overriding Configuration for Special Cases +3.7 Configuring LACP for 802.3ad mode in a more secure way 4. Querying Bonding Configuration 4.1 Bonding Configuration @@ -241,6 +242,21 @@ ad_select This option was added in bonding version 3.4.0. +ad_user_port_key + + In an AD system, the port-key has three parts as shown below - + + Bits Use + 00 Duplex + 01-05 Speed + 06-15 User-defined + + This defines the upper 10 bits of the port key. The values can be + from 0 - 1023. If not given, the system defaults to 0. + + This parameter has effect only in 802.3ad mode and is available through + SysFs interface. + all_slaves_active Specifies that duplicate frames (received on inactive ports) should be @@ -1643,6 +1659,53 @@ output port selection. This feature first appeared in bonding driver version 3.7.0 and support for output slave selection was limited to round-robin and active-backup modes. +3.7 Configuring LACP for 802.3ad mode in a more secure way +---------------------------------------------------------- + +When using 802.3ad bonding mode, the Actor (host) and Partner (switch) +exchange LACPDUs. These LACPDUs cannot be sniffed, because they are +destined to link local mac addresses (which switches/bridges are not +supposed to forward). However, most of the values are easily predictable +or are simply the machine's MAC address (which is trivially known to all +other hosts in the same L2). This implies that other machines in the L2 +domain can spoof LACPDU packets from other hosts to the switch and potentially +cause mayhem by joining (from the point of view of the switch) another +machine's aggregate, thus receiving a portion of that hosts incoming +traffic and / or spoofing traffic from that machine themselves (potentially +even successfully terminating some portion of flows). Though this is not +a likely scenario, one could avoid this possibility by simply configuring +few bonding parameters: + + (a) ad_actor_system : You can set a random mac-address that can be used for + these LACPDU exchanges. The value can not be either NULL or Multicast. + Also it's preferable to set the local-admin bit. Following shell code + generates a random mac-address as described above. + + # sys_mac_addr=$(printf '%02x:%02x:%02x:%02x:%02x:%02x' \ + $(( (RANDOM & 0xFE) | 0x02 )) \ + $(( RANDOM & 0xFF )) \ + $(( RANDOM & 0xFF )) \ + $(( RANDOM & 0xFF )) \ + $(( RANDOM & 0xFF )) \ + $(( RANDOM & 0xFF ))) + # echo $sys_mac_addr > /sys/class/net/bond0/bonding/ad_actor_system + + (b) ad_actor_sys_prio : Randomize the system priority. The default value + is 65535, but system can take the value from 1 - 65535. Following shell + code generates random priority and sets it. + + # sys_prio=$(( 1 + RANDOM + RANDOM )) + # echo $sys_prio > /sys/class/net/bond0/bonding/ad_actor_sys_prio + + (c) ad_user_port_key : Use the user portion of the port-key. The default + keeps this empty. These are the upper 10 bits of the port-key and value + ranges from 0 - 1023. Following shell code generates these 10 bits and + sets it. + + # usr_port_key=$(( RANDOM & 0x3FF )) + # echo $usr_port_key > /sys/class/net/bond0/bonding/ad_user_port_key + + 4 Querying Bonding Configuration ================================= |