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New User
Posts: 1
Registered: ‎03-20-2017
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Administrative distance

Hi everyone,

 

I just wanted to know why Juniper uses different AD values when compared to Cisco?

I've tried to lookup RFC for AD numbering but it looks like it does not exist.

 

Does anyone have a clue if AD numbering is regulated by some "standard", or is it up to vendor to choose the values?

 

Thanks

Recognized Expert
Posts: 129
Registered: ‎12-10-2013
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Re: Administrative distance

Hi !

as far as I know there is NO standard on that

Juniper calls it route preference and not the absolute number is important but the relative position to the preference of competing routing protocols

 

in principle the sequence is quite similar between ciscdo and juniper ( NOT the abosulte value)

the only main and important difference is EBGP ,on cisco it is considered better than any dynamic IGP, on juniper both IBGP and EBGP are considered less preferent than any IGP

 

2017-03-20 17_22_02-JRE-12.a_C2_Routing_Fundamentals.jpg

regards

Alexander

Juniper Employee
Posts: 55
Registered: ‎07-19-2016
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Re: Administrative distance

Hi pp490a,

 

 

There is NO standard for AD.

 

below is an excerpt from wiki

 

Administrative distance (AD) is a number of arbitrary unit assigned to dynamic routes, static routes and directly-connected routes. The value is used by vendor-specific routers to rank routes from most preferred (low administrative distance value) to least preferred (high administrative distance value).When multiple paths to the same destination are available, the router uses the route with the lowest administrative distance and inserts the preferred route into its routing table. Router vendors typically design their routers to assign a default administrative distance to each kind of route that is used, however, this value can usually be set manually by a network administrator.

 

Anand

Trusted Contributor
Posts: 75
Registered: ‎04-26-2015
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Re: Administrative distance

Hi ,

 

Here you can find the AD values in Juniper.

 

 

Understanding Route Preference Values (Administrative Distance)