…but tools have to be used responsibly. first of all, short disclaimer - I’d like to make it perfectly clear before we go into this long piece, that I’m a: …big fan of discussing merits of technology and technology overall. I love technology. I believe having opportunity to create networks, solutions that really connect people and give us chance to exchange information is something I could do for the rest of my life, with full focus and commitment. ...
Daniel Dib asked recently on Twitter about BGP convergence time for world wide operations. two hours he got in response from his friend seemed a bit too long. I did recently help to spin up new ASN with new IPv4 prefix (well, both came from second hand, but you get the point) and as far as I could tell, propagation took around 15 minutes maximum. so in the interest of self-education, I started digging. ...
one of the interesting and rarely seen configuration options, is ability to have redundant IPv6 tunnel established from source address tracked by HSRP. if you’re limited by other side of communication - in this example Hurricane Electric - to have only one endpoint of tunnel on your side that’s right tool for task. the way this configuration would work, is that router active in HSRP pair will be the one on which tunnel will be active and forwarding. we’ll be demonstrating this on IPv6 over IPv4 example, but tunnel type doesn’t really matter. ...
last post in the series about my home lab resulted in a number of interesting emails in my inbox. i have to admit that i really appreciate words of praise. as well as those with constructive, critical feedback :) so after short description what is connected where and how (see link above), let’s focus now on services. first and foremost - remember it’s “always DNS” ;) so let’s tackle that. ...
if you, like me, get bored immediately after you execute copy scp x y, you’ll likely be happy to know that we’re introducing changes in the TCP/IP stack responsible for SCP operations. in NX-OS beginning in 9.3(1), while copying using scp you can add use k-stack, like this: nxos-switch#copy scp://192.168.0.1/nxos.bin bootflash: use-kstack in IOS-XE, starting from 17.2(1), it’s possible to achieve similar speed-up effect by enabling globally ip ssh bulk-mode. the same copy operation should speed up 4-5x over. ...
after last 13 years spent at Cisco Systems Poland, working in the “field” I decided it’s prime time for something new. something, that can challenge me and give back that sense of new adventure. having opportunity to spend all that time with great people, learning a lot and experiencing even more was great fun. i went through full country chain - from “simple” Systems Engineer, to Architecture Lead, Systems Engineer Manager, then Regional Sales Manager (driving 2/3rds of country business operations) and finally Country Systems Engineer Manager and CTO. those thirteen years bring together the best moments (like ability to see your interns grow into SEs and then develop in different roles, or meeting Customers and Partners on countless conferences and events, including Cisco Forum and Cisco Connect) and some of the most challenging and stressful in my life as well. living with weight of your decisions and learning on your own errors, taking ownership of having those hard 1:1 discussions… and ultimately also having to let some people go was really a steep learning curve (and opportunity) i won’t ever forget. some day i may share some of my observations - it’s still too early I believe. ...
every two (or three, depending how desperate you are) years, in life of every CCIE and CCDE there is this looming deadline called ‘recertification’. panic is usually short lived and ends with ‘push’ - succesful recertification. in variable styles and techniques, but successful nonetheless. i had opportunity recently to execute this dance. and wise words people say, that if you loose daily connection with networking gear and technologies, you very quickly loose and forget expert level skills. ...
weekend at countryside kind of suprised me… :) so, Cisco 887VAGW+7-E-K9, a little configuration and here we are. ! chat-script gsm "" "AT!SCACT=1,1" TIMEOUT 15 "OK" ! interface Cellular0 ip address negotiated ip nat outside ip virtual-reassembly in encapsulation slip load-interval 30 dialer in-band dialer idle-timeout 300 dialer string gsm dialer-group 1 async mode interactive ! ip nat translation timeout 60 ip route 0.0.0.0 0.0.0.0 Cellular0 ! dialer-list 1 protocol ip permit ! line 3 exec-timeout 0 0 script dialer gsm modem InOut you’d need to configure profile however. as i didn’t have SIM card and i had poor experience with Orange in Poland, i decided to try challenger - Plus. they had a small sales office in nearby city. ...
it’s interesting to take a look. and then a second look - as a lot of well known networks and hosts appear on those maps: SenderBase malware SenderBase spam and for general SenderBase reports, biggest threat intelligence network go here: SenderBase
…or who needs them anyway today? there’s interesting article written down by one of Google employees, that perfectly describes how ineffective today standard bodies are, and how less and less influence they have on the market. cisco decided to spearhead new solutions without waiting for multi-year discussions, true to the ‘good description and working code’ motto. if we wouldn’t be doing that, there would be no PVLANs, FabricPath (TRILL) but also protocols like LDP or HSRP/VRRP/GLBP. ...