It’s Cisco Netwokers time again; I have been looking forward to this events for months! I find it very dissapointing that Cisco did not deliver a CD-ROM with all the presentations, I hope we get access to them afterwards.
Below is my schedule for this year. I’m always up for a good tech discussion, so poke me if you like to talk about something or exchange thoughts.
Small rant (and solution) about the Belgacom B-Box2 routers their VoIP Support. Please note that this post has nothing to do with the FXS ports on the device itself. I will explain how to implement VoIP support on the LAN network.
By default the Belgacom BBox2 modem will filter UDP 5060 on the LAN so registrations will pass but RTP traffic will not be forwarded leading in uni-directional voice audio. This behavior is for the SIP server in the device itself to make the two FXS ports connect to a VoIP provider; only for those two FXS ports.
This is an understandable default setting from the ISP’s point of view; but really sucks for an Enterprise / B2B customer using VoIP on the LAN.
All you need to do is change the SIP port in “Advanced Settings” – “Telephone” from 5060 to another port. I changed it to 5080 and rebooted the device.
After this small modification SIP registrations and RTP audio will be correctly forwarded.
Today is a special day for all the system administrators our there; a day where they are allowed to be the center of attention.
We usually don’t know who they are, they work in the background keeping things running. Constantly working on improving the infrastructure; being on-call to solve issues at any time of the day.
A big thank you to my employees, colleges and sysadmin friends for the great support and service.
We have just released the latest version of Irssi, please welcome Irssi 0.8.14 to the world! Updated Windows builds will follow soon, keep an eye on the download page.
Most noticable changes include:
Features:
Make /reset an alias for /set -default.
Make /unset an alias for /set -clear.
Allow ctrl+home / ctrl+end to go to the beginning / end of scrollback.
Accept WHOX reply (354 numeric) as a /who reply.
Show numerics directed at channels in the channel window.
The time duration parser is more strict now.
Bugfixes:
Fix out of bounds access in event_wallops().
Build fix for OS X.
Fix the autolog_ignore_targets logic to work correctly with manually opened log files.
Related to my previous post about Pseudowire Redundancy I will now show how to force a switchover from your primary to backup peer.
You can either use the interface or the peer details to force a switchover. Below is the configuration of the PE router configured with a primary and backup peer.
PE#sh run interface GigabitEthernet1/2
Building configuration...
Current configuration : 178 bytes
!
interface GigabitEthernet1/2
description "IP-MPLS # Customer X - noc@customer-X.com"
no ip address
xconnect 192.168.0.2 100 encapsulation mpls
backup peer 192.168.0.3 101 encapsulation mpls
end
PE#
Once again, my sincere apologies to the readers for not posting anything the past few months. Things have been so crazy (the good kind) lately, I just could not find the time to blog. I am very grateful for the thousands of frequent readers, and the few dozen who emailed me for feedback and new posts!
I have received a lot of feedback and requests for specific posts; most requests where related to pseudowire redundancy. So I decided to explain the concept of MPLS L2VPN Pseudowire Redundancy.
Today we will configure a completely redundant MPLS circuit. This type of configuration is most likely the result of an eager sales manager who promised the customer a complete fault-proof solution; with a 99,99999% SLA on top of it.
The following diagram contains one customer circuit; with two backup peers to provide complete fault-tolerance. The primary LSP goes from PE_1 to PE_2, then towards the customer. Should PE_2 become unreachable, or any other problem ocours; PE_1 will setup a connection with it’s backup-peer PE_3.
A similar concept is configured on PE_2, with a primary-peer to PE_1 and a backup-peer going to PE_4 in case PE_1 becomes unreachable. Keep in mind that this concept requires two interfaces going towards the customer at each end of the tail.
I stumbled across this image from NASA. A fascinating view on our own existence.
The large galaxy pictured here contains 8 times as many stars as our own Milky Way Galaxy. It is so large, it technically shouldn’t exist according to current physics theories.
Penultimate Hop Popping is the operation where the outermost label is removed (MPLS POP) from the packet one hop before it’s destination and was implemented to reduce the load on the endpoint routers.
Without PHP the destination router would have to do two label label operations; one to remove the core label identifying the packet destination, and one to process the service label to identify the pseudowire or VRF.
PHP is achieved by the destination router advertising the implicit-null label 3 to it’s neighbor routers for his own loopback address and is the default behavior for LDP.
The past few months I’ve received a lot of feedback on my L2VPN Pseudowire blog post. Most questions where related to tLDP (Targeted LDP), PHP (Penultimate Hop Popping), Implicit Null vs. Explicit Null and pseudowire redundancy configurations.
I will address each of the topics listed above in the upcoming posts, so keep your eyes peeled on this blog and stay tuned! These posts will be explained as easy as possible so everybody with basic networking knowledge will be able to understand them.
Today will explain tLDP, also referred to as Directed LDP and how this is implemented with L2VPN pseudowires.
Targeted LDP sessions are LDP sessions between non-directly connected peers. When a pseudowire is configured, the routers will establish an LDP session and exchange the inner “service” or “application” labels, also known as VC labels.
| tags: 10GigE, Cisco, Cisco Networkers, Cloud Computing, MPLS, NetFlow, Private Cloud, QoS, UC |
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