Category Archives: Automation

Juniper Northstar SDN Controller – Part 2

Following on my earlier blog on Northstar here: https://networkzblogger.com/2017/03/17/juniper-northstar-wan-sdn-controller, recently I got chance to work on next release of it which has among other things is ability to initiate P2MP (Point to Multipoint) LSPs. P2MPs are big use case in Media and Broadcast network and ability to create them via controller would be too helpful. However there is a catch. As discussed in my earlier blog, the NorthStar (NS) Controller relies on PCEP (Path Computation Element Protocol) to deploy a path between the PCC router and PCE (Controller). Currently P2MPs are not initiated by PCEP or its standard is not ratified. So Juniper have come up with another way of configuring it and that’s via Netconf. NETCONF provides mechanisms to install, manipulate, and delete the configuration of network devices. Its operations are realized on top of a simple Remote Procedure Call (RPC) layer. The protocol messages are exchanged on top of a secure transport protocol like SSH etc.

In this blog, instead of looking at PCEP based LSPs from Northstar we will explore netconf functionality and what other features have been introduced in new ns version.

Below is our current model which is built using TED (Traffic Engineering Database) by Northstar and if you look closely there are 2 devices which have PCEP session up because they have correct Junos code on it (15.1F6 and later) however all others are having netconf session Up even if they are on Junos 10, 12, 14 etc. which is cool thing. So as long as you have netconf stanza added in Junos config and have ssh connectivity that is all Northstar need to connect to devices.

Pic-1

Lets start by configuring a P2MP LSP via Northstar

You can see 2 options here for provisioning method. One is PCEP and other is Netconf.

Pic-2

We will choose Netconf and fill other bits.

Pic-3

We have kept Path as dynamic however we can choose required path to TE it more. Under Advanced Tab, you will see P2MP Name field, in which we have added the P2MP name.

Pic-4

All others field you can pretty much keep default.

Once you submit it, Northstar will open a netconf session on port 830 towards headend router which is M320 in our case and push and commit the config to it.

Pic-5

You can see above LSP has become Active and its showing the path as well which this LSP is taking. Now one of the biggest difference between PCEP created LSP and one created from Netconf is that Netconf LSPs will be part of startup-config in Junos as the configs are committing to it so it can be slow process getting your LSP up based upon commit time. Also all Netconf created LSPs are basically shown as PCC Controlled. However PCEP just sent LSP state to network to build E2E path rather than config. PCEP LSP config still resides in NS database and LSPs are created within seconds and are PCE Initiated.

M320> show configuration protocols mpls label-switched-path demo-0610
from 10.198.123.203;
to 10.198.123.103;
p2mp demo-0610-p2p;
primary demo-0610.p0 {
 apply-groups demo-0610-p2p;
}

M320> show configuration groups demo-0610-p2p
protocols {
 mpls {
 label-switched-path <*> {
 primary <*> {
 bandwidth 10m;
 priority 7 7;
 }
 }
 }
}

Ok so that’s for P2MP LSPs which is clean. In 3.1.0 one of the issue we found was related to commit process. Suppose you have 10 LSPs to be created from one source to destination. With Netconf, NS will commit 10 times individually for those LSPs which can be time consuming on some of the MX104s, MX80s with less CPU power. Juniper is looking to change this and putting the commit in batches to decrease the overall time and commit process which would be excellent J

So we have seen now how P2MP LSPs are created via Netconf however we haven’t seen how Netconf parameters are configured on NS as with netconf you can see the analytics data as well which is populated by Telemetry. We will see Telemetry in some other blog.

Under Administration -> Device Profiles we have to set the parameters for individual device.

Pic-6

We enable Netconf and add login details and password. You can test the connectivity as well from NS before actually trying to provision the network.

Pic-7

Apart from P2MP, another thing which has been introduced is while provisioning the LSP you can select which routing method you need to choose. There are many methods starting from default to routebyPCC, etc. default means that NS will calculate the path and routebyPCC means routers will calculate the path and NS won’t be having any say in it.

Pic-8

Another new feature which has been introduced in release 3.1.0 is setting the current path as explicit.

So above P2MP LSP I created was just dynamic however if we want to explicitly make this path as Strict so that LSP doesn’t change path based upon the network conditions we can configure it as below.

Pic-9

If we see the CLI now, NS has filled strict path in it.

M320> show configuration protocols mpls path demo-0610.p0
10.177.177.5 strict;
10.0.0.245 strict;

Ok that’s all for this blog. I hope you like it and let me know your views if you are looking at using NS for your network and if you are already, what are your use cases J

 

R

Mohit Mittal

 

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Ansible on JunOS

Hi All, first of all sorry for coming out late with next blog. Was busy in some personal and official stuff.

Also during past few days, I have been exploring having Ansible set up in our network for ease of configuring and having a centralised place to do some configuration on single or all boxes at once.

Ansible if you don’t know is Configuration Management, software provisioning tool. Ansible is in same league as Puppet, Chef, Salt provisioning tool but its different from them in some sense like Pull vs Push, Stateless vs Stateful etc. We will discuss these difference below but Ansible on top provides configuration/provisioning support for Network engineers in a sense that it has modules from different vendors like Cisco, Huawei, Arista, Nokia and Juniper. We will specifically discuss about Junos here.

Juniper provides support for using Ansible to deploy devices running the Junos operating system (Junos OS). The Juniper Networks Ansible library, which is hosted on the Ansible Galaxy website under the role junos, enables you to use Ansible to perform specific operational and configuration tasks on devices running Junos OS, including installing and upgrading, deploying specific devices in the network, loading configuration changes, retrieving information, and resetting, rebooting, or shutting down managed devices.

I have just started to explore Ansible so I am really Amateur in this area however may be after some months of work I will be in position to provide more details on this 🙂 . Before we dive into some examples let’s review what I said before regarding differences.

Push vs Pull –> Puppet basically works on Pull mechanism where its hosts periodically pulls the configurations from server which is good for some things but not if you want change to deployed asap. On the other hand Ansible works in Push model where config is applied instantly to nodes/hosts.

Stateless vs Stateful –> Ansible works in stateless mode where to use Ansible, nothing needs to be installed on Hosts i.e. switches/routers. Ansible and other libraries are installed on Server which is controller and it connects to nodes/hosts via SSH/Netconf.

For Ansible to work with Junos, 3 requirements needs to be fulfilled first on server.

1)      pip install ncclient  (this is python lib for netconf)

2)      pip install junos-eznc (this is python lib for Junos)

3)      Install Juniper.junos Galaxy role using command:

ansible-galaxy install Juniper.junos

Once this is done, we can run raw modules from Ansible server as Ad-hoc commands which basically uses SSH instead of netconf.

I am running ansible on CentOS 6.9

 

mmittal@ANS01$ cat /etc/redhat-release
CentOS release 6.9 (Final)

So basically here we will be using raw module to check the version on host and we will provide the username with it and –k option will invoke us to put password.

ansible -v 10.198.123.103 -m raw -a "show version" -u mmittal –k
SSH password:
10.198.123.103 | SUCCESS | rc=0 >>
Hostname: MX-104-PE-Volvo
Model: mx104
Junos: 15.1F6.9
JUNOS Base OS boot [15.1F6.9]
JUNOS Base OS Software Suite [15.1F6.9]
JUNOS Crypto Software Suite [15.1F6.9]
JUNOS Packet Forwarding Engine Support (MX104) [15.1F6.9]
JUNOS Web Management [15.1F6.9]
JUNOS Online Documentation [15.1F6.9]
JUNOS Services Application Level Gateways [15.1F6.9]
JUNOS Services Jflow Container package [15.1F6.9]
JUNOS Services Stateful Firewall [15.1F6.9]
JUNOS Services NAT [15.1F6.9]
JUNOS Services RPM [15.1F6.9]
JUNOS Services Captive Portal and Content Delivery Container package [15.1F6.9]
JUNOS Macsec Software Suite [15.1F6.9]
JUNOS Services Crypto [15.1F6.9]
JUNOS Services IPSec [15.1F6.9]
JUNOS Kernel Software Suite [15.1F6.9]
JUNOS Routing Software Suite [15.1F6.9]
Shared connection to 10.198.123.103 closed.

This adhoc commands lets you check things without having to do any real programming however real use of Ansible comes via way of playbooks which are basically scripts in layman term. Under playbook we will mention the module which want to run and tasks to be performed. Before running Ansible playbook it is better to talk about one important file name called ansible.cfg which basically resides in etc/ansible/ansible.cfg

However ansible.cfg is picked up in following order and it is recommended to have our own ansible.cfg in current/home directory so that we can control the parameters we want to have.

* ANSIBLE_CONFIG (an environment variable)
* ansible.cfg (in the current directory)
* .ansible.cfg (in the home directory)
* .ansible.cdg (in /etc/ansible/ansible.cfg)

Example from my ansible.cfg which apart from standard defaults is also pointing to hostfile where all IP Addresses of routers/switches will reside.

mmittal@ANS01$ cat ansible.cfg
[defaults]
hostfile = ./ansible_hosts
host_key_checking = false
timeout = 5
log_path=./ansible.log

Lets see one example of playbook.

So in this playbook we are adding a task of running multiple commands on 2 hosts and module we have used in junos_command and we are printing the output on session.

mmittal@ANS01$ cat ansible_multiplecommands.yml
---
- name: show version and other user level commands
 hosts: 10.198.123.100, 10.198.123.103
 roles:
 - Juniper.junos
 gather_facts: no
 connection: local
tasks:
 - name: run multiple commands on remote nodes
 junos_command:
 commands:
 - show version
 - show interfaces

register: print_output

- debug: var=print_output.stdout_lines

To run this playbook we have to use the following command:

mmittal@ANS01$ ansible-playbook ansible_multiplecommands.yml -u mmittal -k
SSH password:

PLAY [show version and other user level commands] *************************************************************************************************************************************************************

TASK [run multiple commands on remote nodes] ******************************************************************************************************************************************************************
ok: [10.198.123.103]
ok: [10.198.123.100]

TASK [debug] **************************************************************************************************************************************************************************************************
ok: [10.198.123.100] => {
 "print_output.stdout_lines": [
 [
 "Hostname: re1.MX104_PE_Pagani",
 "Model: mx104",
 "Junos: 15.1F6.9",
 "JUNOS Base OS boot [15.1F6.9]",
 "JUNOS Base OS Software Suite [15.1F6.9]",
 "JUNOS Crypto Software Suite [15.1F6.9]",
 "JUNOS Packet Forwarding Engine Support (MX104) [15.1F6.9]",
 "JUNOS Web Management [15.1F6.9]",
 "JUNOS Online Documentation [15.1F6.9]",
 "JUNOS Services Application Level Gateways [15.1F6.9]",
 "JUNOS Services Jflow Container package [15.1F6.9]",
 "JUNOS Services Stateful Firewall [15.1F6.9]",
 "JUNOS Services NAT [15.1F6.9]",
 "JUNOS Services RPM [15.1F6.9]",
 "JUNOS Services Captive Portal and Content Delivery Container package [15.1F6.9]",
 "JUNOS Macsec Software Suite [15.1F6.9]",
 "JUNOS Services Crypto [15.1F6.9]",
 "JUNOS Services IPSec [15.1F6.9]",
 "JUNOS Kernel Software Suite [15.1F6.9]",
 "JUNOS Routing Software Suite [15.1F6.9]"
 ],
 [
 "Physical interface: ge-0/0/0, Enabled, Physical link is Up",
 " Interface index: 154, SNMP ifIndex: 512",
 " Description: Connected to MX104 RR-3_ge-0/1/0",
 " Link-level type: Ethernet, MTU: 1600, MRU: 1608, LAN-PHY mode,",
 " Speed: 1000mbps, BPDU Error: None, MAC-REWRITE Error: None,",
 " Loopback: Disabled, Source filtering: Disabled, Flow control: Enabled,",
 " Auto-negotiation: Enabled, Remote fault: Online",
 " Pad to minimum frame size: Disabled",
 " Device flags : Present Running",
 " Interface flags: SNMP-Traps Internal: 0x0",
 " CoS queues : 8 supported, 8 maximum usable queues",
 " Current address: 54:1e:56:f7:78:00, Hardware address: 54:1e:56:f7:78:00",
 " Last flapped : 2017-08-18 13:32:41 GMT (2w3d 21:51 ago)",
 .
.
(o/p trunacated)
.
.
.
.
 ]
 ]
}
ok: [10.198.123.103] => {
 "print_output.stdout_lines": [
 [
 "Hostname: MX-104-PE-Volvo",
 "Model: mx104",
 "Junos: 15.1F6.9",
 "JUNOS Base OS boot [15.1F6.9]",
 "JUNOS Base OS Software Suite [15.1F6.9]",
 "JUNOS Crypto Software Suite [15.1F6.9]",
 "JUNOS Packet Forwarding Engine Support (MX104) [15.1F6.9]",
 "JUNOS Web Management [15.1F6.9]",
 "JUNOS Online Documentation [15.1F6.9]",
 "JUNOS Services Application Level Gateways [15.1F6.9]",
 "JUNOS Services Jflow Container package [15.1F6.9]",
 "JUNOS Services Stateful Firewall [15.1F6.9]",
 "JUNOS Services NAT [15.1F6.9]",
 "JUNOS Services RPM [15.1F6.9]",
 "JUNOS Services Captive Portal and Content Delivery Container package [15.1F6.9]",
 "JUNOS Macsec Software Suite [15.1F6.9]",
 "JUNOS Services Crypto [15.1F6.9]",
 "JUNOS Services IPSec [15.1F6.9]",
 "JUNOS Kernel Software Suite [15.1F6.9]",
 "JUNOS Routing Software Suite [15.1F6.9]"
 ],
 [
 "Physical interface: lc-0/0/0, Enabled, Physical link is Up",
 " Interface index: 142, SNMP ifIndex: 506",
 " Speed: 800mbps",
 " Device flags : Present Running",
 " Link flags : None",
 " Last flapped : Never",
 " Input packets : 0",
 " Output packets: 0",
 "",
 " Logical interface lc-0/0/0.32769 (Index 329) (SNMP ifIndex 507)",
 " Flags: Encapsulation: ENET2",
 " Bandwidth: 0",
 " Input packets : 0",
 " Output packets: 0",
 " Protocol vpls, MTU: Unlimited",
 " Flags: Is-Primary",
 "",
(o/p trunacated)
.
.
.
 ]
 ]
}

PLAY RECAP ****************************************************************************************************************************************************************************************************
10.198.123.100 : ok=2 changed=0 unreachable=0 failed=0
10.198.123.103 : ok=2 changed=0 unreachable=0 failed=0

 


So that’s all for today.. Its very basic intro to Ansible on Junos however I hope you get an idea and will try to use it in your network 🙂

Regards

Mohit