RSVP Configuration Commands

RSVP Configuration Commands

RSVP is disabled on router interfaces and this is the default interface state. In order for a router to participate in RSVP, RSVP must be enabled on the interfaces using the command

ip rsvp bandwidth [interface-kbps] [single-flow-kbps]

interface-kbpsOptional parameter. Value can be 1—10,000,000.

Optional parameter. Value can be 1—10,000,000.

The parameters shown in brackets are optional parameters. The first optional parameter is the total amount of bandwidth that will be reserved on the interface for RSVP flows. The second optional parameter is the amount of bandwidth that can be allocated to a single flow.

By default 75 percent of the bandwidth on an interface can be reserved.

Example

For the router in Figure 10-34, reserve 75 percent of the bandwidth on the ethernet interfaces with a limit of 10 percent of the bandwidth for any one flow.

Figure 10-32: IPv4 RESV_CONFIRM object; Class-Num = 15 C-Type = 1

Figure 10-33: IPv6 RESV_CONFIRM object; Class-Num = 15 C-Type = 2

Figure 10-34: Enabling RSVP and reserving bandwidth on router interfaces

interface Ethernet 0

ip address 10.1.1.1 255.255.255.0

ip pim dense-mode

ip rsvp bandwidth 7500 1000

interface Ethernet 1

ip address 10.1.1.1 255.255.255.0

ip pim dense-mode

ip rsvp bandwidth 7500 1000

To disable RSVP on an interface, use the command

no ip rsvp bandwidth interface-kbps single-flow-kbps

By default, any neighbor can request a reservation on a router interface. If only selected neighbors are to be permitted to request a reservation using RSVP, we would use the interface command

ip rsvp neighbors access-list-number

access-list-number

Integer from 1 to 199. 1 to 99 for a standard access list. 100—199 for an extended access list.

In Figure 10-35, we want to only permit the receiver with IP address 10.1.4.2 to be able to request a reservation. There is an implicit deny any at the end of every access list. Therefore the access list in Figure 10-35 will block all other receivers from requesting reservations. If we wanted to only block 10.1.4.2 from making a reservation but permit any other receiver to request a reservation then we would need the access list shown in Figure 10-36. The permit any is required because of the implicit deny any at the end of the list.

Figure 10-35: Allow only sender 10.1.4.2 to request a reservation

Figure 10-36: Deny sender 10.1.4.2 from requesting a reservation

Router C

interface Ethernet 0

ip address 10.1.4.1 255.255.255.0

ip pim dense-mode

ip rsvp bandwidth

ip rsvp neighbors 1

access-list 1 permit host 10.1.4.1

Router C

interface Ethernet 0

ip address 10.1.4.1 255.255.255.0

ip pim dense-mode

ip rsvp bandwidth

ip rsvp neighbors 1

access-list 1 deny host 10.1.4.1

access-list 1 permit any

To remove an access list for a neighbor, use the interface command

no ip rsvp neighbors access-list-number

We have seen that RSVP will periodically send refresh messages for PATH and RESV messages. The refresh messages keep the path and reservation states in place by preventing them from timing out. The router can be configured to behave as though it were receiving reservation or path messages using

ip rsvp sender session-ip-address sender-ip-address

[tcp|udp|ip-protocol] session-dport sender-sport

previous-hop-ip-address previous-hop-interface bandwidth burst-size

for PATH messages and

ip rsvp reservation session-ip-address sender-ip-address

[tcp|udp|ip-protocol] session-dport sender-sport

next-hop-ip-address next-hop-interface

{ff|se|wf} {rate|load} bandwidth burst-size

for RESV messages. The explanations of the parameters for the two messages are listed below.

session-ip-address

For a unicast session, this is the address of the receiver. For a multicast session, this is the session IP multicast address.

sender-ip-address

IP address of the sender.

tcp|udp|ip-protocol

session dport session sport

Destination and source port numbers. If one is zero then both must be zero.

previous-hop-ip-address

Address of the sender if the sender is connected to the interface or address of the router interface on the path back to the sender.

previous-hop-interface

Interface type of the previous hop. It can be ethernet, loopback, null, or serial.

next-hop-ip-address

Hostname or address of the receiver or the address of the router interface on the path back to the receiver.

next-hop-interface

Interface type of the next hop. Can be ethernet, loopback, null, or serial.

:ff | se | wf

Reservation style: fixed filter, shared explicit, or wild card.

rate | load

QoS: guaranteed bit rate service or controlled load service.

bandwidth

Optional. Average bit rate (kbps) to reserve, up to 75 percent of the interface capacity. Range is 1 to 10,000,000.

burst-size

Optional. Maximum burst size (kilobytes of data in the queue). Range is 1 to 65,535.

To remove the effect these commands, use the form

no ip rsvp sender session-ip-address sender-ip-address

[tcp|udp|ip-protocol] session-dport sender-sport

previous-hop-ip-address previous-hop-interface bandwidth burst-size

for PATH messages and

no ip rsvp reservation session-ip-address sender-ip-address

[tcp|udp|ip-protocol] session-dport sender-sport

next-hop-ip-address next-hop-interface

{ff|se|wf} {rate|load} bandwidth burst-size

for RESV messages.

In Figure 10-37, routers A and C are configured so the sender path state and the receivers reservation never time out.

Router A

Interface Ethernet0 ip address 10.1.1.2 255.255.255.0 ip pim dense-mode ip rsvp bandwidth ip rsvp sender 225.1.1.1 10.1.1.1 udp 20 30 10.1.1.1 ethernet0 50 5

Figure 10-37: Example of static RSVP reservations

Router C

interface Ethernet0 ip address 10.1.4.1 255.255.255.0 ip pim dense-mode ip rsvp bandwidth ip rsvp reservation 255.1.1.1 10.1.4.2 ethernet0 ff rate 300 60

The final RSVP configuration command addresses the encapsulation of the RSVP messages. If the router detects that RSVP neighbors are using UDP encapsulation, the router will automatically generate UDP encapsulated messages. In some situations, a host will not originate a message unless it has heard from the router. To configure the router to generate UDP encapsulated RSVP multicasts, use the command

ip rsvp udp-multicast multicast-address