The worst feeling for a geek:
Courtesy of xkcd (http://xkcd.com/979/)
This has happened to me twice now: upgrading Mac OS X from one release to another and after the dust settles, the search function in Outlook 2011 totally breaks and always returns “no results”. As we all know, email sucks and being able to deftly search through that mound of crap in your mail client is the only thing that makes it somewhat bearable.
Check Point firewall upgrades have always been painful. The loss of connection state is a big part of this. Existing connections stop working, and many applications need restart. It looks like there is a way of minimising this pain on upgrade.
Stateful firewalls record the current ‘state’ of traffic passing through, so they can recognise and allow reply or related traffic. If you have a firewall cluster, they need to synchronise state between the cluster members. This is so that if there is a failover, the new Active node will be aware of all connections currently in flight.
If you have a failover, and the standby member is NOT aware of current connection state, it will drop all currently open sessions. Any packet that isn’t a SYN packet will get dropped, and the applications need to establish new connections. Some applications handle this well – especially those that use many short-lived connections such as HTTP or DNS. But other applications that have long-running connections – e.g. DB connections – may struggle with this. They think the connection is still open, and take a long time to figure out it’s broken. They may eventually recover on their own, or they may Continue reading
Departing the lovely, sterile, electronic testing center after passing the final CCNP Route/Switch exam, and I’m on the way to the local pub to celebrate. You know what I’m already thinking about: gotta ride that wave, right? Stoke the flames, feet off the pedals down the hill, ride the momentum up the next, and all […]
The post CCIE sponsorship proposal example appeared first on Packet Pushers Podcast and was written by quingenerd.
HP IMC installation is normally a manual process, with plenty of clickey clickey clickey. This is OK for production systems, as most sites will only have one or maybe two IMC servers. But for my lab, I wanted to automate the install, so I can quickly spin up a new lab system. I have now found an undocumented, unsupported way of doing this.
There’s two parts to this – preparing the underlying OS & DB, and installing IMC. I am writing Ansible playbooks to handle the OS + DB setup. That’s working, but it needs a bit of cleanup. Once that’s done, I’ll integrate it with Vagrant. Then I should be able to completely automate the install of a lab IMC system. I will write another post on that once it’s complete.
To install IMC silently, create an “install.cfg” file to define your settings. Then tweak the installation script to call the silent installer, not the interactive install.
If you have BT broadband and want to graph the synced speed and actual use of your broadband connection, and you use the BT provided router (Home Hub), then you can’t use SNMP to get these counters. But you can get the data over HTTP without too much trouble. Here’s some ugly one-liners for doing that.
curl -s 192.168.42.1/nonAuth/wan_conn.xml \
| sed -r '/wan_conn_volume_list/{N;s/.*\[.//;s/[^0-9]\],$//;s/%3B/ /g;s/^[0-9]+ ([0-9]+) ([0-9]+)$/\1 \2/g;p};d'
curl -s 192.168.42.1/nonAuth/wan_conn.xml \
| sed -r '/status_rate/{N;s/.*\[.//;s/[^0-9]\],$//;s/%3B/ /g;s/^([0-9]+) ([0-9]+) [0-9]+ [0-9]+/\2 \1/g;p};d'
First I tried this. And it appeared to work. But only if someone had logged in to the web UI recently.
curl -s 192.168.42.1/cgi/cgi_ad_B_Internet.js \
| sed -r '/wan_conn_volume_list/{N;s/.*\[.//;s/[^0-9]\],$//;s/%3B/ /g;s/.* ([0-9]+) ([0-9]+)$/\1 \2/g;p};d'
But then I try it on a different machine and… Oh… oh no. Oh say it ain’t so. Don’t tell me the BT home hub security is based on IP address? Oh… oh it is.
Yet another reason these routers are completely retarded. Other examples:
If you have BT broadband and want to graph the synced speed and actual use of your broadband connection, and you use the BT provided router (Home Hub), then you can’t use SNMP to get these counters. But you can get the data over HTTP without too much trouble. Here’s some ugly one-liners for doing that.
curl -s 192.168.42.1/nonAuth/wan_conn.xml
| sed -r '/wan_conn_volume_list/{N;s/.*[.//;s/[^0-9]],$//;s/%3B/ /g;s/^[0-9]+ ([0-9]+) ([0-9]+)$/1 2/g;p};d'
curl -s 192.168.42.1/nonAuth/wan_conn.xml
| sed -r '/status_rate/{N;s/.*[.//;s/[^0-9]],$//;s/%3B/ /g;s/^([0-9]+) ([0-9]+) [0-9]+ [0-9]+/2 1/g;p};d'
First I tried this. And it appeared to work. But only if someone had logged in to the web UI recently.
curl -s 192.168.42.1/cgi/cgi_ad_B_Internet.js | sed -r '/wan_conn_volume_list/{N;s/.*[.//;s/[^0-9]],$//;s/%3B/ /g;s/.* ([0-9]+) ([0-9]+)$/1 2/g;p};d'
But then I try it on a different machine and… Oh… oh no. Oh say it ain’t so. Don’t tell me the BT home hub security is based on IP address? Oh… oh it is.
Yet another reason these routers are completely retarded. Other examples:
Guess who's building a hypervisor! Also, Huawei backs ONOS and Red Hat cranks up virtual storage.
A good knowledge of Cisco’s Documentation is what could make a difference in passing or failing the exam. Because of that, I would like to show you how to access most useful Doc CD resources on a per blueprint-section basis. In addition, we will also take a look at the location of a particular document, so you know how to access it without using the Search function. Same thing as what you will have to do to access those resources in the lab.
Unless otherwise mentioned, all documents discussed in this blog are part of Configuration Guides.
Probably the most useful doc here will be for Control Plane features. However, I am going to show you more so you at least know how to find them.
Our starting point for this section is IOS Configuration Guides :
IOS and NX-OS Software -> IOS -> IOS Software Release 15M&T -> 15.2M&T
IP Routing : RIP -> Configuring Routing Information Protocol
http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_rip/configuration/15-mt/irr-15-mt-book/irr-cfg-info-prot.html
IP Routing : EIGRP -> IP EIGRP Route Authentication
http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_eigrp/configuration/15-mt/ire-15-mt-book/ire-rte-auth.html
IP Routing : EIGRP -> IPv6 Routing : EIGRP Support
http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_eigrp/configuration/15-mt/ire-15-mt-book/ip6-route-eigrp.html
Continue reading
We took a short ride to Boston this week’s for Arrow’s Internet of Things Immersions Conference. Dave Husak, our CTO and EVP of products and technology, participated in a panel alongside executives from Arrow, EMC, Intel, NXP and Oracle to discuss the role software defined networking will play in future Big Data deployments. Dave spoke to why innovative infrastructure is necessary to manage mixed workloads and big data jobs of different priorities. Interested in seeing Plexxi in action? We’ll be on the road for the next few months—stay tuned or drop us a line at [email protected] for more information.
Below please find a few of our top picks for our favorite news articles of the week. Have a great weekend!
Light Reading: Open Networking Acronym Soup
By Marc Cohn
During the past few years, software-defined networking (SDN) and network functions virtualization (NFV) have emerged as the next big thing in networking. As a result, we’ve seen established networking standards development organizations (SDOs) such as the ITU, IETF, TMF, among others, leap on the bandwagon to address SDN and NFV. In addition, many new industry groups have been created, including the ONF, ETSI NFV ISG and ONUG, not to mention Continue reading