Март | 2017

Иногда есть имя коробки, но нет адреса loopback, чтобы его узнать «побыстрому» воспользуемся ISIS(Huawei):

<MPLS-R1>dis isis lsdb is-name MPLS-R10 verbose
                       Database information for ISIS(10)
                       ----------------------------------
                          Level-2 Link State Database
LSPID                 Seq Num      Checksum      Holdtime      Length  ATT/P/OL
-------------------------------------------------------------------------------
0101.2000.0254.00-00  0x0000bc63   0x71ae        945           268     0/0/0
 SOURCE       MPLS-R10.00
 HOST NAME    MPLS-R10
 NLPID        IPV4
 AREA ADDR    65.3440
 INTF ADDR    10.120.0.254
 INTF ADDR    172.220.7.118
 INTF ADDR    172.220.7.121
+NBR  ID      MPLS-R11.00 COST: 10
+NBR  ID      MPLS-R12.00 COST: 10
+IP-Extended  10.120.0.254    255.255.255.255  COST: 0
+IP-Extended  172.220.7.116    255.255.255.252  COST: 10
+IP-Extended  172.220.7.120    255.255.255.252  COST: 10
 Router ID    10.120.0.254

Total LSP(s): 1
    *(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),
           ATT-Attached, P-Partition, OL-Overload

<MPLS-R1>dis isis lsdb is-name MPLS-R10 verbose

Database information for ISIS(10)

----------------------------------

Level-2 Link State Database

LSPID Seq Num Checksum Holdtime Length ATT/P/OL

-------------------------------------------------------------------------------

0101.2000.0254.00-00 0x0000bc63 0x71ae 945 268 0/0/0

SOURCE MPLS-R10.00

HOST NAME MPLS-R10

NLPID IPV4

AREA ADDR 65.3440

INTF ADDR 10.120.0.254

INTF ADDR 172.220.7.118

INTF ADDR 172.220.7.121

+NBR ID MPLS-R11.00 COST: 10

+NBR ID MPLS-R12.00 COST: 10

+IP-Extended 10.120.0.254 255.255.255.255 COST: 0

+IP-Extended 172.220.7.116 255.255.255.252 COST: 10

+IP-Extended 172.220.7.120 255.255.255.252 COST: 10

Router ID 10.120.0.254

Total LSP(s): 1

*(In TLV)-Leaking Route, *(By LSPID)-Self LSP, +-Self LSP(Extended),

ATT-Attached, P-Partition, OL-Overload

Вот он наш loopback cо стоимостью ноль.

<MPLS-R1>telnet 10.120.0.254
Trying 10.120.0.254 ...
Press CTRL+K to abort
Connected to 10.120.0.254 ...
Warning: Telnet is not a secure protocol, and it is recommended to use Stelnet.
Username:

<MPLS-R1>telnet 10.120.0.254

Trying 10.120.0.254 ...

Press CTRL+K to abort

Connected to 10.120.0.254 ...

Warning: Telnet is not a secure protocol, and it is recommended to use Stelnet.

Username:

<MPLS-R10>dis cur conf isis
#
isis 10
 is-name MPLS-R10
#

<MPLS-R10>dis cur conf isis

isis 10

is-name MPLS-R10

Juniper:

R1> show isis database MPLS-R10 detail
IS-IS level 1 link-state database:
IS-IS level 2 link-state database:

MPLS-R10.00-00 Sequence: 0xbc68, Checksum: 0x67b3, Lifetime: 1110 secs
IS neighbor: MPLS-R12.00 Metric: 10
IS neighbor: MPLS-R13.00 Metric: 10
IP prefix: 10.120.0.254/32 Metric: 0 Internal Up
IP prefix: 172.220.7.116/30 Metric: 10 Internal Up
IP prefix: 172.220.7.120/30 Metric: 10 Internal Up

R1> show isis database MPLS-R10 detail

IS-IS level 1 link-state database:

IS-IS level 2 link-state database:

MPLS-R10.00-00 Sequence: 0xbc68, Checksum: 0x67b3, Lifetime: 1110 secs

IS neighbor: MPLS-R12.00 Metric: 10

IS neighbor: MPLS-R13.00 Metric: 10

IP prefix: 10.120.0.254/32 Metric: 0 Internal Up

IP prefix: 172.220.7.116/30 Metric: 10 Internal Up

IP prefix: 172.220.7.120/30 Metric: 10 Internal Up

При крэше процессов/демонов в Junos они автоматически перезапускаются, посмотрим на примере RPD как это реализовано, это применимо и к другим процессам.

root@R1% ps auxww | grep rpd
root  2298  0.0  1.7 65540 18024  ??  S     2:08PM   0:00.12 /usr/sbin/rpd -N

1 2	root@R1% ps auxww \| grep rpd root 2298 0.0 1.7 65540 18024 ?? S 2:08PM 0:00.12 /usr/sbin/rpd -N

root@R1% kill 2298
root@R1% ps auxww | grep rpd
root  2938  1.4  1.7 64516 17272  ??  S     2:14PM   0:00.07 /usr/sbin/rpd -N

root@R1% kill 2298

root@R1% ps auxww | grep rpd

root 2938 1.4 1.7 64516 17272 ?? S 2:14PM 0:00.07 /usr/sbin/rpd -N

Видно, что rpd перезапустился автоматически, тоже самое произойдет при крэше:

root@R1> show system core-dumps no-forwarding
/var/crash/*core*: No such file or directory
-rw-------  1 root  wheel  168041054 May 20  2016 /var/tmp/rpd.core-tarball.0.tgz
-rw-rw----  1 root  wheel  560058368 May 20  2016 /var/tmp/rpd.core.0

root@R1> show system core-dumps no-forwarding

/var/crash/*core*: No such file or directory

-rw------- 1 root wheel 168041054 May 20 2016 /var/tmp/rpd.core-tarball.0.tgz

-rw-rw---- 1 root wheel 560058368 May 20 2016 /var/tmp/rpd.core.0

RPD стартует «из под» init , и используется параметр respawn для перезапуска:

root@R1% grep -r "/usr/sbin/rpd -N" /etc/*
/etc/init.conf:    command "/usr/sbin/rpd -N";

1 2	root@R1% grep -r "/usr/sbin/rpd -N" /etc/* /etc/init.conf: command "/usr/sbin/rpd -N";

root@R1% cat /etc/init.conf
process "routing" {
    action respawn;
    command "/usr/sbin/rpd -N";
    dump-command "/bin/sh /etc/dumpd rpd";
    alarm red id 5;
    re-mode protocol-master;
    protocol-mastership signal hup;
    low-memory signal;
}

root@R1% cat /etc/init.conf

process "routing" {

action respawn;

command "/usr/sbin/rpd -N";

dump-command "/bin/sh /etc/dumpd rpd";

alarm red id 5;

re-mode protocol-master;

protocol-mastership signal hup;

low-memory signal;

}

Кусок из руководства:

man init(5)
respawn
  A service    or task    with this stanza will be automatically started
  if it should stop    abnormally.  All reasons for a service stop-
  ping,  except  the stop(8) command itself, are considered abnor-
  mal.Tasks may exit with a zero exit status to prevent being
  respawned.

man init(5)

respawn

A service or task with this stanza will be automatically started

if it should stop abnormally. All reasons for a service stop-

ping, except the stop(8) command itself, are considered abnor-

mal.Tasks may exit with a zero exit status to prevent being

respawned.

IPv5

Архив за месяц: Март 2017

Loopback по ISIS имени

Junos: Перезапуск процессов при крэше/etc

Networking