Routing
Highlighted
Routing

Reg : IOS to JUNOS conversion

‎06-30-2016 11:39 PM

Dear All,

 

                I am new to the junos , We have a MX-104 router with two ISP links . MX104 will replace the cisco 7206 router . Any one please help me in converting the IOS configuration to the JUNOS. I have done configuration on juniper mx104 . Herewith i have attached the BGP configuration on IOS and JUNOS. Need your help in BGP configuration on the MX104.

 

 

Thanks & Regards

Maheswaran

s.mahes85@gmail.com

Attachments

8 REPLIES 8
Highlighted
Routing

Re: Reg : IOS to JUNOS conversion

‎06-30-2016 11:45 PM

Online IOS to Junos convertor

https://i2j.juniper.net/release/index.jsp

 

 

http://kb.juniper.net/InfoCenter/index?page=content&id=kb15482&actp=search

Thanks,
Suraj
Please Mark My Solution Accepted if it Helped, Kudos are Appreciated too
Highlighted
Routing

Re: Reg : IOS to JUNOS conversion

‎06-30-2016 11:54 PM

Dear Suraj,

 

                 Thank you for your response , I have done the configuration based on the I2J output . Now BGP got up and working fine with out issues but the reverse path for all the network is passing through ISP-2(TATA) . Please have a look at the attached cisco configuration , while cisco in place the traffic for network 203.223.188.0/24 is coming through ISP-2(TATA)  and reverse path for all other network is coming through ISP-1(AIRTEL).

 

Thanks & Regards

Maheswaran

Highlighted
Routing

Re: Reg : IOS to JUNOS conversion

‎07-01-2016 01:39 AM

Hi,

 

It might be easier if you could describe the desired output/behavior.

I assume by reverse path, you mean inbound traffic.

 

What I gathered from the Cisco config is you are applying local-preference of 500 to specific prefixes towards TCL [To-TCL] and AES [To-AES out]. However, since this eBGP I doubt local-preference would be the method to influence your inbound traffic, unless I missed something..

 

I believe the export policies could have been simplified by rewritting them.

 

You can use "show route table inet.0 advertising-protocol bgp x.x.x.x" to view the routes being announced to the neighbors. If you have a similar capture before the migration, you could compare against as well.

 

Cheers,

Ashvin

Highlighted
Routing

Re: Reg : IOS to JUNOS conversion

‎07-01-2016 10:51 PM

Hi Ashvin,

 

             Thank you for your reply . I am mentioning about inbound traffic only . I have attached the "show route table inet.0 advertising-protocol bgp x.x.x.x " output , In that we could see all the networks are advertised in both TCL and AIRTEL. Can you please guide me for changes in Juniper bgp config which is attached earlier . I dont have the output of the route table before migration .

 

Thanks & Regards

Maheswaran

Attachments

Highlighted
Routing

Re: Reg : IOS to JUNOS conversion

[ Edited ]
‎07-03-2016 05:02 PM

Hi,

 

Had few observations with regards to the output:

1.  I believe the announcement is for IP Transit and can see some prefixes longer than /24. As a best practice, it is recommended not to announce longer than /24 prefixes

http://archive.apnic.net/meetings/22/docs/tut-routing-pres-bgp-bcp.pdf

 

2.  From the cisco config, I gathered prefixes in AES-ip & TCL-ip were being set local-preference of 500 towards AS9498 and AS4755 respectively. However, since this is eBGP, the local-preference attribute is only local within an AS and does not get announced with the set local-preference to eBGP peers.

 

To influence inbound routing for specific prefixes, AS-PATH preprend would be more appropriate.

 

3.  The order of the export policies is also important in the configuration. For example:

set protocols bgp group group-1 neighbor 14.142.79.177 export bgp-redistributes
set protocols bgp group group-1 neighbor 14.142.79.177 export bgp-policies-group-1-1-export

Policy "bgp-redistributes" already contains accept actions, hence the same prefix does not get evaluated in the next policy. Re-ordering the policy can be beneficial.

 

There are different ways to configure the policy for AS-PATH preprend. An example could be as below:

Spoiler
set policy-options prefix-list EXPORT-BGP 103.21.76.0/24
set policy-options prefix-list EXPORT-BGP 123.255.250.0/24
set policy-options prefix-list EXPORT-BGP 123.255.251.0/24
set policy-options prefix-list EXPORT-BGP 203.223.188.0/24
set policy-options prefix-list EXPORT-BGP 203.223.189.0/24
set policy-options prefix-list EXPORT-BGP 203.223.190.0/24
set policy-options prefix-list EXPORT-BGP 203.223.191.0/24

set policy-options prefix-list AES-AS-PREPEND 203.223.188.0/24
set policy-options prefix-list AES-AS-PREPEND 203.223.189.0/24

set policy-options prefix-list TCL-AS-PREPEND 43.225.164.0/24
set policy-options prefix-list TCL-AS-PREPEND 103.21.76.0/24
set policy-options prefix-list TCL-AS-PREPEND 123.255.250.0/24
set policy-options prefix-list TCL-AS-PREPEND 123.255.251.0/24
set policy-options prefix-list TCL-AS-PREPEND 203.223.190.0/24
set policy-options prefix-list TCL-AS-PREPEND 203.223.191.0/24

set policy-options policy-statement AES-AS-PREPEND term AES-PREPEND from prefix-list-filter AES-AS-PREPEND exact
set policy-options policy-statement AES-AS-PREPEND term AES-PREPEND then as-path-prepend "45536 45536"
set policy-options policy-statement AES-AS-PREPEND term AES-PREPEND then next policy

set policy-options policy-statement TCL-AS-PREPEND term TCL-PREPEND from prefix-list-filter TCL-AS-PREPEND exact
set policy-options policy-statement TCL-AS-PREPEND term TCL-PREPEND then as-path-prepend "45536 45536"
set policy-options policy-statement TCL-AS-PREPEND term TCL-PREPEND then next policy

set policy-options policy-statement EXPORT-BGP term EXPORT-STATIC from protocol static
set policy-options policy-statement EXPORT-BGP term EXPORT-STATIC from prefix-list-filter EXPORT-BGP exact
set policy-options policy-statement EXPORT-BGP term EXPORT-STATIC then accept
set policy-options policy-statement EXPORT-BGP term EXPORT-BGP from prefix-list-filter EXPORT-BGP exact
set policy-options policy-statement EXPORT-BGP term EXPORT-BGP then community delete all
set policy-options policy-statement EXPORT-BGP term EXPORT-BGP then accept
set policy-options policy-statement EXPORT-BGP term DEFAULT then reject

set protocols bgp group group-1 neighbor 14.142.79.177 export TCL-AS-PREPEND
set protocols bgp group group-1 neighbor 14.142.79.177 export EXPORT-BGP

set protocols bgp group group-2 neighbor 72.14.194.177 export AES-AS-PREPEND
set protocols bgp group group-2 neighbor 72.14.194.177 export EXPORT-BGP

It's important that the order of the export policies is in the correct order. Example:

export [ TCL-AS-PREPEND EXPORT-BGP ];

 As mentioned before, there could be other ways of writing export policies to achieve the same objective.

 

Hope this helps.

 

Cheers,

Ashvin

Highlighted
Routing

Re: Reg : IOS to JUNOS conversion

‎07-04-2016 10:59 PM

Dear Ashvin,

 

                   Thanks for the input , Based on your input i have created a template for changing the existing configuration . I am planning to remove the existing bgp configuration completely and reconfigure based on the attached template . Herewith i have attached the topology diagram . Please suggest for any changes in the template . 

 

 

Thanks,

Mahesh

Attachments

Highlighted
Routing

Re: Reg : IOS to JUNOS conversion

‎07-06-2016 03:55 AM

Hi,

 

The config template looks ok.

Based on the topology, I am not sure if you have any BGP routes that need to be announced to transits, so below term may not be matched:

set policy-options policy-statement EXPORT-BGP term EXPORT-BGP

You could also aggregate some of the prefixes and announce the aggregate route. Example:

set routing-options aggregate route 123.255.250.0/23
set routing-options aggregate route 203.223.188.0/22
set policy-options policy-statement EXPORT-BGP term EXPORT-AGGREGATE from route-filter 123.255.250.0/23 exact
set policy-options policy-statement EXPORT-BGP term EXPORT-AGGREGATE from route-filter 203.223.188.0/22 exact
set policy-options policy-statement EXPORT-BGP term EXPORT-AGGREGATE then accept
set policy-options policy-statement EXPORT-BGP term EXPORT-STATIC from protocol static
set policy-options policy-statement EXPORT-BGP term EXPORT-STATIC from prefix-list-filter EXPORT-BGP exact
set policy-options policy-statement EXPORT-BGP term EXPORT-STATIC then accept
set policy-options policy-statement EXPORT-BGP term DEFAULT then reject

This could be another method for influencing inbound traffic, by exporting part of the /24s at either transit but the global aggregate at both.

 

Hope this helps.

 

Cheers,

Ashvin

 

 

 

Routing

Re: Reg : IOS to JUNOS conversion

‎07-17-2016 11:51 PM

Dear Ashvin,

 

                    We have another requirement we need to advertise network 103.21.78.0/24 in airtel and Tata but need to restrict the network from being advertised in GOOGLE . Kindly advise based on the template attached in the previous post. As per our current configuration , if i advertise the network 103.21.78.0/24 is getting advertised with all the BGP peers i.e airtel,tata and Google. Herewith i have attached the current configuration.

 

We have done the intial configuration based on the I2J output . Kindly give ur suggestion or make changes in the template attached in the previous post , we will reconfigure the BGP based on the template.

 

 

Thanks 

Mahesh

Attachments

Feedback