It took me a bit of struggling to figure out how to pull configuration subtrees via NetConf. Part of this was because I was using tags instead of . But also, I was hitting 256 character line-limits.

I’ll work that out later… the main reason for this post is to document what I found on how to get configuration subtrees. This particular example fetches the subtree for a specific neighbor under [protocols l2circuit].

To structure the rpc request, we use the command “get-config” and specify a source of candidate. Then we add a “filter” tag with an attribute of @type=“subtree” and under that we can specify the configuration subtree as xml tags.

<rpc message-id="1002 Tue Jun 17 23:25:48 -0400 2014">
    <get-config>
        <source><candidate/></source>
        <filter type="subtree">
            <configuration>
                <protocols>
                    <l2circuit>
                        <neighbor>
                            <name>192.168.104.69</name>
                        </neighbor>
                    </l2circuit>
                </protocols>
            </configuration>
        </filter>
    </get-config>
</rpc>
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This is the reply I got.

rpc-reply xmlns="urn:ietf:params:xml:ns:netconf:base:1.0" xmlns:junos="http://xml.juniper.net/junos/12.3R4/junos" message-id="1002 Tue Jun 17 23:25:48 -0400 2014">
    <get-config>
        <source><candidate/></source>
        <filter type="subtree">
            <configuration>
                <protocols>
                    <l2circuit>
                        <neighbor>
                            <name>192.168.104.69</name>
                        </neighbor>
                    </l2circuit>
                </protocols>
            </configuration>
        </filter>
    </get-config>
</rpc>
<data>
<configuration xmlns="http://xml.juniper.net/xnm/1.1/xnm" junos:changed-seconds="1402600329" junos:changed-localtime="2014-06-12 19:12:09 UTC">
    <protocols>
        <l2circuit>
            <neighbor>
                <name>192.168.104.69</name>
                <interface>
                    <name>ae0.3909</name>
                    <virtual-circuit-id>55509</virtual-circuit-id>
                </interface>
                <interface>
                    <name>ae0.3933</name>
                    <virtual-circuit-id>55533</virtual-circuit-id>
                </interface>
                <interface>
                    <name>ae0.3959</name>
                    <virtual-circuit-id>55559</virtual-circuit-id>
                </interface>
                <interface>
                    <name>ae0.3983</name>
                    <virtual-circuit-id>55583</virtual-circuit-id>
                </interface>
                <interface>
                    <name>ae0.3991</name>
                    <virtual-circuit-id>55591</virtual-circuit-id>
                </interface>
            </neighbor>
        </l2circuit>
    </protocols>
</configuration>
</data>
</rpc-reply>
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My particular application in this case was that I wanted to get the interface associated with a certain virtual-circuit-id and neighbor. This made it easy to collect what I wanted and to also present the xml for logging.