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Silly question for a Friday
I can "show route <hostname>" and JUNOS will do a DNS lookup and show
the route for the resolved IP. Is there any way to control that for
hosts with multiple IPs, especially IPv6?
--
Chris Adams <cma@cmadams.net>
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Re: Silly question for a Friday [ In reply to ]
show route family inet/inet6 <host>

On Fri, Jun 7, 2019, 4:43 PM Chris Adams <cma@cmadams.net> wrote:

> I can "show route <hostname>" and JUNOS will do a DNS lookup and show
> the route for the resolved IP. Is there any way to control that for
> hosts with multiple IPs, especially IPv6?
> --
> Chris Adams <cma@cmadams.net>
> _______________________________________________
> juniper-nsp mailing list juniper-nsp@puck.nether.net
> https://puck.nether.net/mailman/listinfo/juniper-nsp
>
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Re: Silly question for a Friday [ In reply to ]
Sorry, I'm thinking of ping/traceroutes..

On Fri, Jun 7, 2019, 4:49 PM Tim Jackson <jackson.tim@gmail.com> wrote:

> show route family inet/inet6 <host>
>
> On Fri, Jun 7, 2019, 4:43 PM Chris Adams <cma@cmadams.net> wrote:
>
>> I can "show route <hostname>" and JUNOS will do a DNS lookup and show
>> the route for the resolved IP. Is there any way to control that for
>> hosts with multiple IPs, especially IPv6?
>> --
>> Chris Adams <cma@cmadams.net>
>> _______________________________________________
>> juniper-nsp mailing list juniper-nsp@puck.nether.net
>> https://puck.nether.net/mailman/listinfo/juniper-nsp
>>
>
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Re: Silly question for a Friday [ In reply to ]
Hey Chris,

> I can "show route <hostname>" and JUNOS will do a DNS lookup and show
> the route for the resolved IP. Is there any way to control that for
> hosts with multiple IPs, especially IPv6?

Not that I am aware of. But in your mind, how would this ideally work,
how do you control which A record is returned without communicating
the A record? Or would you just have it print route for all of them?
Certainly you could write python op script to do that.

ytti@r25.dllstx09.us.bb-re0> start shell command "dig +short microsoft.com A"
104.215.148.63
13.77.161.179
40.76.4.15
40.112.72.205
40.113.200.201
ytti@r25.dllstx09.us.bb-re0> show route 13.77.161.179 | resolve

inet.0: 788394 destinations, 12285824 routes (786249 active, 1
holddown, 430224 hidden)
+ = Active Route, - = Last Active, * = Both

13.64.0.0/11 *[BGP/170] 3w3d 18:11:21, MED 4294967294, localpref
100, from r10.dllstx09.us.bb.gin.ntt.net
AS path: 174 8075 I, validation-state: unverified
> to ae-13.r10.dllstx09.us.bb.gin.ntt.net via ae2.0



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++ytti
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Re: Silly question for a Friday [ In reply to ]
Once upon a time, Saku Ytti <saku@ytti.fi> said:
> > I can "show route <hostname>" and JUNOS will do a DNS lookup and show
> > the route for the resolved IP. Is there any way to control that for
> > hosts with multiple IPs, especially IPv6?
>
> Not that I am aware of. But in your mind, how would this ideally work,
> how do you control which A record is returned without communicating
> the A record? Or would you just have it print route for all of them?
> Certainly you could write python op script to do that.

Possibly print the route for each returned record (minimizing to only
show each path once would be a bonus). The bigger thing that got me
thinking about this is that there's no way to say "show route <host>"
and see the IPv6 route instead of the IPv4 route (for the case of a host
with just one A and AAAA record). I guess JUNOS does the DNS resolution
and picks what to look up before it gets to looking at what table you've
asked for (so adding "table inet6.0" doesn't work).

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Chris Adams <cma@cmadams.net>
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