Network system and network redundancy method
In a network system in which a switch forwarding packets and a control server determining route information are separated, it is desired to achieve a redundancy of the control channel by an out-of-band control channel and an in-band control channel, when the switch receives a control message regarding the flow entry registration and the like based on the route information from the control server. Specifically, the separated switch and control server are connected by a control channel for sending and receiving the control message. The switch is not only connected to a control server via an out-of-band control channel by a route dedicated to the control message, but also connected to another control server via an in-band control channel by a route which is common with a normal data communication for determining the route information, to achieve a redundancy of the control channel.
1. A network system comprising:
a switch configured to forward a packet;
an out-of-band control server configured to send a control message to the switch via an out-of-band control channel to determine route information; and
an in-band control server configured to send a control message to the switch via an in-band control channel to determine route information, wherein
the out-of-band control server is configured to:
establish the out-of-band control channel with the switch; and
set route information for the in-band control channel between the switch and the in-band control server.
2. The network system according to claim 1 , wherein the switch is configured to:
establish the in-band control channel with the in-band control server; and
constitute a redundancy structure of a control server by using both of the out-of-band control server and the in-band control server.
3. The network system according to claim 2 , wherein the switch is configured to:
monitor a fault of both of the out-of-band control channel and the in-band control channel; and
switch an active control channel to a stand-by control channel among the out-of-band control channel and the in-band control channel when the fault occurs.
4. A computer which is used as at least one of the switch, the out-of-band control server, and the in-band control server according to the network system according to claim 2 .
5. The network system according to claim 2 , wherein the switch is configured to:
monitor a fault of both of the out-of-band control channel and the in-band control channel; and
switch an active control channel to a stand-by control channel among the out-of-band control channel and the in-band control channel when the fault occurs.
6. A computer which is used as at least one of the switch, the out-of-band control server, and the in-band control server according to the network system according to claim 5 .
7. A computer which is used as at least one of the switch, the out-of-band control server, and the in-band control server according to the network system according to claim 2 .
8. A network redundancy method comprising:
forwarding a packet by a switch;
sending a control message from an out-of-band control server to the switch via an out-of-band control channel to determine route information; and
sending a control message from an in-band control server to the switch via an in-band control channel to determine route information;
establishing the out-of-band control channel by the out-of-band control server with the switch; and
setting route information for the in-band control channel between the switch and the in-band control server by the out-of-bend control server.
9. The network redundancy method according to claim 8 , further comprising:
establishing the in-band control channel with the in-band control server by the switch; and
constituting a redundancy structure of a control server by the switch by using both of the out-of-band control server and the in-band control server.
10. The network redundancy method according to claim 9 , further comprising:
monitoring a fault of both of the out-of-band control channel and the in-band control channel by the switch; and
switching an active control channel to a stand-by control channel among the out-of-band control channel and the in-band control channel by the switch when the fault occurs.
11. A non-transitory recording medium which stores a program when executed by a processor to make a computer functions as each of the switch, the out-of-band control server, and the in-band control server according to the network redundancy method according to claim 9 .
12. The network redundancy method according to claim 8 , further comprising:
monitoring a fault of both of the out-of-band control channel and the in-band control channel by the switch; and
switching an active control channel to a stand-by control channel among the out-of-band control channel and the in-band control channel by the switch when the fault occurs.
13. A non-transitory recording medium which stores a program when executed by a processor to make a computer functions as each of the switch, the out-of-band control server, and the in-band control server according to the network redundancy method according to claim 8 .