[j-nsp] New to Juniper: loopback interface address for the re0 configuration group?

[Olivier Benghozi]

lo0.0 interface is to be configured under "set interfaces lo0 blah". Because you really don't want a changing lo0 IP if there's a switchover.
Usually in re0/1 groups for MX (or member0/1 for Virtual Chassis EX switches, or member0/1-re0/1 for Virtual Chassis MX) you define a hostname mentioning re0/re1, and some OOB interface stuff (fpx0, if you use it).

So, again a poorly written documentation (written to illustrate one and only one function in fact, not to have a globally working config).

By the way you'll also benefit from reading doc about non-stop-routing: http://www.juniper.net/documentation/en_US/junos14.2/topics/task/configuration/nsr-configuring.html <http://www.juniper.net/documentation/en_US/junos14.2/topics/task/configuration/nsr-configuring.html>
This is what makes dual-RE something really useful, after all.


> Le 9 mai 2016 à 14:37, v <vekt0r7 at gmx.net> a écrit :
> 
> Thank you!
> 
> However, if I understand correctly that configuration snippet is from the fxp0 interface. I can't see an lo0 interface being mentioned anywhere in your configuration. Which part of your configuration comes from "set re0 interfaces lo0 unit 0 family inet address [address/prefix-length]"?
> 
> Regards,
> v
> 
> Am 2016-05-09 um 14:19 schrieb Raphael Maunier:
>> Here the config for the 2 re
>> groups {
>>     re0 {
>>         system {
>>             host-name re0.mx1.fqdn;
>>         }
>>         interfaces {
>>             fxp0 {
>>                 unit 0 {
>>                     family inet {
>>                         address 10.10.10.9/24 {
>>                             master-only;
>>                         }
>>                         address 10.10.10.10/24;
>>                     }
>>                 }
>>             }
>>         }
>>     }
>>     re1 {
>>         system {
>>             host-name re1.mx2.fqdn;
>>         }
>>         interfaces {
>>             fxp0 {
>>                 unit 0 {
>>                     family inet {
>>                         address 10.10.10.9/24 {
>>                             master-only;
>>                         }
>>                         address 10.10.10.11/24;
>>                     }
>>                 }
>>             }
>>         }
>>     }
>> 
>>     And then apply-group [re0 re1]
>> 
>> 
>> 
>> 
>> 
>> Raphael
>> 
>> On 09/05/16 14:11, "juniper-nsp on behalf of v" <juniper-nsp-bounces at puck.nether.net on behalf of vekt0r7 at gmx.net> wrote:
>> 
>>> Hello,
>>> 
>>> I am new to networking and trying to understand the initial configuration on a Juniper MX router with dual REs:
>>> http://www.juniper.net/techpubs/en_US/junos14.2/topics/task/configuration/routing-engine-dual-initial-configuration.html
>>> 
>>> Step 6 is the following:
>>> " Set the loopback interface address for the re0 configuration group:
>>> [edit groups]
>>> root at host# set re0 interfaces lo0 unit 0 family inet address address/prefix-length"
>>> 
>>> Why do I need to give the re0 group a loopback interface address in the first place?
>>> What address should I give to the loopback interface?
>>> 
>>> Regards,
>>> v