24.4.2 Load Balancing Specifications
The following table describes the specifications for multipath routing on the Switch.
Item |
Specifications |
Remarks |
---|---|---|
Number of multipaths for a single destination network |
2~16 |
- |
Maximum number of multipaths that can be specified in the configuration |
1 to 16 (Multipath is not generated when 1 is specified) |
The maximum number of multipaths is specified for each routing protocol. |
Maximum number of multipath routes |
The value differs depending on the maximum number of multipaths handled by the switch. For details, see Table 24-6: Maximum number of multipath routes. |
- |
Routing protocols capable of generating multipaths |
|
- |
Number of multipaths in a default configuration |
|
- |
Prefix length of the routes used |
0~127 |
If the prefix length of the route is 128, multiple paths (next hop data) are registered with the forwarding table as a single path. The next hop address used at this point is the same as the address displayed at top when the show ipv6 route operation command is executed. |
Connection method |
Can be used with any combination of line type and interface type. Concurrent use of different types of lines or interfaces is possible. |
Multipaths between VRFs are not supported. |
Maximum number of multipaths set in the configuration*1 |
Handle by the device Maximum number of multipaths*2 |
Maximum number of multipath routes that can be handled*2*3*4 |
---|---|---|
1~4 |
4 |
1024 (512 #6) |
5~8 |
8 |
512 (256 #6) |
9 to 16, or multipath unused*5 |
16 |
256 (128 #6) |
Using static routing as an example, the following table shows how the maximum multipath values change as you change the device configuration or restart the device.
Seq. |
Status |
Maximum number of multipaths for static routing |
Maximum number of multipaths handled by the switch |
---|---|---|---|
1 |
The switch starts without static routing configured. |
- |
16 |
2 |
You add a static route. |
6 #1 |
16 |
3 |
The switch restarts. |
6 |
8 |
4 |
Set the maximum number of multipaths for static routing to 3 |
3 |
8 |
5 |
The switch restarts. |
3 |
4 |
6 |
You set the maximum multipath count for static routing to 5. |
4 #2 |
4 |
7 |
The switch restarts. |
5 #2 |
8 |
The following table describes the load balancing specifications implemented by the Switch.
Item |
Specifications |
Remarks |
---|---|---|
Path selection in multipaths |
A value (hash value) is calculated and allocated to the designated output path. This hash value is derived from the following four fields:
For packets with the same hash value, the same output path is selected. This guarantees the transmission order. |
- |
Multipath information in routing table |
Hash values are assigned on a substantially equal basis to the output interfaces in the routing table. |
[24.4.3 See 1 in "Precautions When Using Load Balancing" |
Weighting of paths |
Not available |
|
Processing of packets exceeding output bandwidth |
Not reallocated to another path. The packets are retained within the switch as long as bandwidth continues to be exceeded. However, any overflow will be discarded. |