1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
|
# Graceful Restart
This page explains how to configure [Graceful Restart](https://tools.ietf.org/html/rfc4724),
[Graceful Restart Notification Support](https://tools.ietf.org/html/draft-ietf-idr-bgp-gr-notification-07) and
[Long Lived Graceful Restart](https://tools.ietf.org/html/draft-uttaro-idr-bgp-persistence-02).
Graceful Restart has two sides. One is restarting speaker which does restart,
the other is receiving speaker (helper speaker) which helps a restarting speaker
to do graceful restart. GoBGP supports both roles.
## Contents
- [Helper speaker](#helper-speaker)
- [Restarting speaker](#restarting-speaker)
- [Graceful Restart Notification Support](#graceful-restart-notification-support)
- [Long Lived Graceful Restart](#long-lived-graceful-restart)
- [Long Lived Graceful Restart Helper Speaker Configuration](#long-lived-graceful-restart-helper-speaker-configuration)
- [Long Lived Graceful Restart Restarting Speaker Configuration](#long-lived-graceful-restart-restarting-speaker-configuration)
- [Combination with normal Graceful Restart](#combination-with-normal-graceful-restart)
## Helper speaker
Below is the configuration to enable helper speaker behavior.
```toml
[global.config]
as = 64512
router-id = "192.168.255.1"
[[neighbors]]
[neighbors.config]
neighbor-address = "10.0.255.1"
peer-as = 65001
[neighbors.graceful-restart.config]
enabled = true
```
Check graceful restart capability is negotiated.
```shell
$ gobgp n 10.0.255.1
BGP neighbor is 10.0.255.1, remote AS 65001
BGP version 4, remote router ID 192.168.0.2
BGP state = BGP_FSM_ESTABLISHED, up for 00:00:36
BGP OutQ = 0, Flops = 0
Hold time is 0, keepalive interval is 30 seconds
Configured hold time is 90, keepalive interval is 30 seconds
Neighbor capabilities:
BGP_CAP_MULTIPROTOCOL:
RF_IPv4_UC: advertised and received
BGP_CAP_ROUTE_REFRESH: advertised and received
BGP_CAP_GRACEFUL_RESTART: advertised and received
Remote: restart time 90 sec
RF_IPv4_UC
BGP_CAP_FOUR_OCTET_AS_NUMBER: advertised and received
Message statistics:
Sent Rcvd
Opens: 1 1
Notifications: 0 0
Updates: 2 1
Keepalives: 2 2
Route Refresh: 0 0
Discarded: 0 0
Total: 5 4
Route statistics:
Advertised: 1
Received: 0
Accepted: 0
```
## Restarting speaker
To support restarting speaker behavior, try the configuration below.
```toml
[global.config]
as = 64512
router-id = "192.168.255.1"
[[neighbors]]
[neighbors.config]
neighbor-address = "10.0.255.1"
peer-as = 65001
[neighbors.graceful-restart.config]
enabled = true
restart-time = 120
[[neighbors.afi-safis]]
[neighbors.afi-safis.config]
afi-safi-name = "ipv4-unicast"
[neighbors.afi-safis.mp-graceful-restart.config]
enabled = true
```
By this configuration, if graceful restart capability is negotiated with the peer,
the peer starts graceful restart helper procedure, when `gobgpd` dies involuntarily or
`SIGINT`, `SIGKILL` signal is sent to `gobgpd`.
Note when `SIGTERM` signal is sent to `gobgpd`, graceful restart negotiated peers
don't start graceful restart helper procedure, since `gobgpd` sends notification
messages to these peers before it die.
When you restart `gobgpd`, add `-r` option to let peers know `gobgpd` is
recovered from graceful restart.
```shell
$ gobgpd -f gobgpd.conf -r
```
Let's see how capability negotiation changes.
```shell
$ gobgp n 10.0.255.1
BGP neighbor is 10.0.255.1, remote AS 65001
BGP version 4, remote router ID 192.168.0.2
BGP state = BGP_FSM_ESTABLISHED, up for 00:00:03
BGP OutQ = 0, Flops = 0
Hold time is 0, keepalive interval is 30 seconds
Configured hold time is 90, keepalive interval is 30 seconds
Neighbor capabilities:
BGP_CAP_MULTIPROTOCOL:
RF_IPv4_UC: advertised and received
BGP_CAP_ROUTE_REFRESH: advertised and received
BGP_CAP_GRACEFUL_RESTART: advertised and received
Local: restart time 90 sec, restart flag set
RF_IPv4_UC, forward flag set
Remote: restart time 90 sec
RF_IPv4_UC
BGP_CAP_FOUR_OCTET_AS_NUMBER: advertised and received
Message statistics:
Sent Rcvd
Opens: 1 1
Notifications: 0 0
Updates: 2 1
Keepalives: 1 1
Route Refresh: 0 0
Discarded: 0 0
Total: 4 3
Route statistics:
Advertised: 1
Received: 0
Accepted: 0
```
You can see `restart flag` and `forward flag` is set.
Without `-r` option, the peers which are under helper procedure will
immediately withdraw all routes which were advertised from `gobgpd`.
Also, when `gobgpd` doesn't recovered within `restart-time`, the peers will
withdraw all routes.
Default value of `restart-time` is equal to `hold-time`.
## Graceful Restart Notification Support
[RFC4724](https://tools.ietf.org/html/rfc4724) specifies gracful restart procedures are triggered only when
the BGP session between graceful restart capable peers turns down without
a notification message for backward compatibility.
[Graceful Restart Notification Support](https://tools.ietf.org/html/draft-ietf-idr-bgp-gr-notification-07)
expands this to trigger graceful restart procedures also with a notification message.
To turn on this feature, add `notification-enabled = true` to configuration like below.
```toml
[global.config]
as = 64512
router-id = "192.168.255.1"
[[neighbors]]
[neighbors.config]
neighbor-address = "10.0.255.1"
peer-as = 65001
[neighbors.graceful-restart.config]
enabled = true
notification-enabled = true
```
## Long Lived Graceful Restart
### Long Lived Graceful Restart Helper Speaker Configuration
```toml
[global.config]
as = 64512
router-id = "192.168.255.1"
[[neighbors]]
[neighbors.config]
neighbor-address = "10.0.255.1"
peer-as = 65001
[neighbors.graceful-restart.config]
enabled = true
long-lived-enabled = true
```
### Long Lived Graceful Restart Restarting Speaker Configuration
Unlike normal graceful restart, long-lived graceful restart supports
restart-time as per address family.
```toml
[global.config]
as = 64512
router-id = "192.168.255.1"
[[neighbors]]
[neighbors.config]
neighbor-address = "10.0.255.1"
peer-as = 65001
[neighbors.graceful-restart.config]
enabled = true
long-lived-enabled = true
[[neighbors.afi-safis]]
[neighbors.afi-safis.config]
afi-safi-name = "ipv4-unicast"
[neighbors.afi-safis.long-lived-graceful-restart.config]
enabled = true
restart-time = 100000
```
### Combination with normal Graceful Restart
You can also use long lived graceful restart with normal graceful restart.
```toml
[global.config]
as = 64512
router-id = "192.168.255.1"
[[neighbors]]
[neighbors.config]
neighbor-address = "10.0.255.1"
peer-as = 65001
[neighbors.graceful-restart.config]
enabled = true
long-lived-enabled = true
restart-time = 120
[[neighbors.afi-safis]]
[neighbors.afi-safis.config]
afi-safi-name = "ipv4-unicast"
[neighbors.afi-safis.mp-graceful-restart.config]
enabled = true
[neighbors.afi-safis.long-lived-graceful-restart.config]
enabled = true
restart-time = 100000
```
|
