Tag Archives: Junos cheat sheet

JUNIPER JUNOS COMMAND SERIES – 3

Hi All, lets continue our useful Junos command series by looking at 2 more interesting commands. One is another flexibility which Juniper provides and 2nd is to see the command structure in way which can be directly pasted on CLI.

So this is our example policy config from MX104:

MX104-PE> show configuration policy-options policy-statement test
term 1 {
 from community test;
 then accept;
}
term 2 {
 from neighbor 1.1.1.1;
 then accept;
}
term 3 {
 then reject;

Now lets suppose you need to add one term (term 4) between before term 3 so that it doesn’t get reject by last reject term. Lets puts a term 4 and see what’s the result.

[edit policy-options policy-statement test]
MX104-PE# set term 4 from family inet

[edit policy-options policy-statement test]
MX104-PE# set term 4 then accept
[edit policy-options policy-statement test]
MX104-PE# show
term 1 {
 from community test;
 then accept;
}
term 2 {
 from neighbor 1.1.1.1;
 then accept;
}
term 3 {
 then reject;
}
term 4 {
 from family inet;
 then accept;
}

Now if you see above Junos has added the term 4 at the end which won’t be useful to us if we commit now as term 3 is reject and term 4 won’t be validated at all because of reject term 3 above it. So to get away with this problem Junos provides us one command “insert” which will insert the term 4 before term 3. Let’s see it in action.

[edit policy-options policy-statement test]
MX104-PE# insert term 4 before term 3

[edit policy-options policy-statement test]
MX104-PE# show
term 1 {
 from community test;
 then accept;
}
term 2 {
 from neighbor 1.1.1.1;
 then accept;
}
term 4 {
 from family inet;
 then accept;
}
term 3 {
 then reject;
}

Now lets check the another command which is very easy hack

Sometimes you need the configuration from Juniper in set form so that you can paste it directly on the other or same box after some modifications.

This is our example configuration:

show configuration interfaces ge-0/1/8
vlan-tagging;
mtu 1522;
encapsulation vlan-ccc;
unit 601 {
 encapsulation vlan-ccc;
 vlan-id 601;
 family ccc;
}

Now to get the set form of this configuration, Junos gives us this command:
show configuration interfaces ge-0/1/8 | display set
set interfaces ge-0/1/8 vlan-tagging
set interfaces ge-0/1/8 mtu 1522
set interfaces ge-0/1/8 encapsulation vlan-ccc
set interfaces ge-0/1/8 unit 601 encapsulation vlan-ccc
set interfaces ge-0/1/8 unit 601 vlan-id 601
set interfaces ge-0/1/8 unit 601 family ccc

This is exact same config but in separate form and can be easily copy pasted from top edit mode on other device.

In next blogs we will see more commands to copy paste the config without set form.

So that’s all, I hope you liked this article as well and will make use of these commands in your day to day operational work or troubleshooting.

Regards

Mohit Mittal

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Juniper JunOS Command Series – 1

Hi All, from this series we will look at some useful JunOS commands and concepts where Juniper give us flexibility over other vendors and I hope this will help you in case you are switching from other vendor products to JunOS.

We will look at example from interface configuration however same can be applied to any stanza or part of configuration in Junos.

Lets start with configuration of interface ge-0/0/7 where 3 logical units have been defined and this link is made to participate in 3 vlans correspondingly.

MX104> show configuration interfaces ge-0/0/7
description Test;
vlan-tagging;
unit 100 {
    vlan-id 100;
    family inet {
        address 10.10.10.5/30;
    }
}
unit 200 {
    vlan-id 200;
    family inet {
        address 10.10.10.9/30;
    }
}
unit 300 {
    vlan-id 300;
    family inet {
        address 10.10.10.13/30;
    }
}

However later some requirement change and because of it you need to change the ip addressing on one of the unit from 10.10.10.5 to say 20.20.20.5.

Now one way of doing this in Junos is to configure the new address in below fashion!!

MX104>edit
Entering configuration mode

[edit]
MX104# edit interfaces ge-0/0/7

[edit interfaces ge-0/0/7]
MX104# set unit 100 family inet address 20.20.20.5/30

But this has created an additional row under the interface stanza for which we have to write one delete statement to delete previous 10.10.10.5 address.

[edit interfaces ge-0/0/7]
MX104# show
description Test;
vlan-tagging;
unit 100 {
    vlan-id 100;
    family inet {
        address 10.10.10.5/30;
        address 20.20.20.5/30;
    }
}
unit 200 {
    vlan-id 200;
    family inet {
        address 10.10.10.9/30;
    }
}
unit 300 {
    vlan-id 300;
    family inet {
        address 10.10.10.13/30;
    }
}
 
[edit interfaces ge-0/0/7]
MX104#delete unit 100 family inet address 10.10.10.5/30

Final config is:

[edit interfaces ge-0/0/7]
MX104# show
description Test;
vlan-tagging;
unit 100 {
    vlan-id 100;
    family inet {
        address 20.20.20.5/30;
    }
}
unit 200 {
    vlan-id 200;
    family inet {
        address 10.10.10.9/30;
    }
}
unit 300 {
    vlan-id 300;
    family inet {
        address 10.10.10.13/30;
    }
}

This method is fine for one change however not a very quick method. Junos gives us ability to change this value in very quick way by using “rename” command.

(NOTE: I did rollback the changes made above before proceeding further in order for interface configuration to be at same stage from where I started my blog)

Rename command renames the value of particular variable to new value and you need to mention the whole command hierarchy or go to level where you want the change to be applied. This is easy method to achieve same thing in less number of changes.

[edit interfaces ge-0/0/7]
MX104# rename unit 100 family inet address 10.10.10.5/30 to address 20.20.20.5/30

[edit interfaces ge-0/0/7]
MX104# show
description Test;
vlan-tagging;
unit 100 {
    vlan-id 100;
    family inet {
        address 20.20.20.5/30;
    }
}
unit 200 {
    vlan-id 200;
    family inet {
        address 10.10.10.9/30;
    }
}
unit 300 {
    vlan-id 300;
    family inet {
        address 10.10.10.13/30;
    }
}

Now, what if you want to change all IP Addresses under interface ge-0/0/7 stanza to use 20.20.20.x address rather than 10.10.10.x.. 2 methods can be set/delete and rename as we saw above however we have to define 2 rename statements in our case to change the ip addresses on remaining unit 200 and unit 300.

Again Junos is to the rescue and this time we will use another command “replace”. Replace command replaces the pattern you want to be replaced with new pattern.

Let’s see it in action.

Below is our configuration after we changed unit 100 with new ip address using rename command.

MX104> show configuration interfaces ge-0/0/7
description Test;
vlan-tagging;
unit 100 {
    vlan-id 100;
    family inet {
        address 20.20.20.5/30;
    }
}
unit 200 {
    vlan-id 200;
    family inet {
        address 10.10.10.9/30;
    }
}
unit 300 {
    vlan-id 300;
    family inet {
        address 10.10.10.13/30;
    }
} 

Now we have to change the ip addresses on unit 200 and unit 300 and in that case we can achieve this by using below command:

[edit interfaces ge-0/0/7]
MX104# replace pattern 10.10.10 with 20.20.20

[edit interfaces ge-0/0/7]
MX104# show
description Test;
vlan-tagging;
unit 100 {
    vlan-id 100;
    family inet {
        address 20.20.20.5/30;
    }
}
unit 200 {
    vlan-id 200;
    family inet {
        address 20.20.20.9/30;
    }
}
unit 300 {
    vlan-id 300;
    family inet {
        address 20.20.20.13/30;
    }
}

Pretty exciting and fast !!! 🙂

One thing to remember is that you have to be in exact hierarchy where you want this pattern to be replaced. If you are at the Top level i.e under edit hierarchy only, then this will replace all instances of 10.10.10 with 20.20.20 whereever it is in whole config and not just ge-0/0/7.

Let’s see this in action one more time.

below is our configuration resulting from replace method. Now lets assume that we have to change all units and accordingly vlan’s last 2 digits from 00 to 10.. so unit and vlan id needs to be changed from 100, 200 and 300 to 110, 210, and 310 respectively.

[edit interfaces ge-0/0/7]
MX104# show
description Test;
vlan-tagging;
unit 100 {
    vlan-id 100;
    family inet {
        address 20.20.20.5/30;
    }
}
unit 200 {
    vlan-id 200;
    family inet {
        address 20.20.20.9/30;
    }
}
unit 300 {
    vlan-id 300;
    family inet {
        address 20.20.20.13/30;
    }
}


[edit interfaces ge-0/0/7]
MX104# replace pattern 00 with 10

[edit interfaces ge-0/0/7]
MX104# show
description Test;
vlan-tagging;
unit 110 {
    vlan-id 110;
    family inet {
        address 20.20.20.5/30;
    }
}
unit 210 {
    vlan-id 210;
    family inet {
        address 20.20.20.9/30;
    }
}
unit 310 {
    vlan-id 310;
    family inet {
        address 20.20.20.13/30;
    }
}

So that’s all, I hope you liked this article and will make use of these commands in your day to day operational work or troubleshooting. In future blogs we will see more useful commands and till then, have a nice day..

 

Regards

Mohit Mittal