Came across this excellent presentation of Peter Hoose (Facebook). It gives a very good logical way of troubleshooting problems. Less about actual problems but about how Ops members companies like Facebook troubleshoot them.
This is from NANOG 64. Enjoy the presentation. :)
Few days back a friend of mine (who works for an ISP) congratulated me for joining HE. Along with wishes he told me that our bgp.he.net doesn’t works well and the reason he fealt so is because he couldn’t see all peers for his ASN in our tool.
This is not a problem and to be more broader - same applies on all popular tools other then bgp.he.net like RIPE Stats, Robtex AS analysis etc. The reason many of these tools do not and cannot show all peers is because they show what they see from the point of collection. E.g right now I am on BSNL (AS9829).
Just was looking around at EDNS support by Google. To find how it supports and how packet looks like I created a test NS records for dnstest.anuragbhatia.com pointing to one of test server (178.238.225.247). I wasn’t running any DNS server on the server. Just ran quick tcpdump.
At server end:
sudo tcpdump 'port 53 and dst 178.238.225.247' -nn -vvv -w sample.pcap
Then I forcefully triggered DNS queries via Google’s recursor using:**
Few months ago I moved away from Google Chrome to Opera Mobile on my Android device. Google Chrome is pretty loaded and overall slow. Recently I noticed browsing was pretty slow. I noticed that “Off-Road mode” was enabled.
I disabled it and performance was much better. I did heard of it in past and clearly it’s a proxy mode where packets between Opera instance running on cell phone and destination server are routed via an Opera server which uses some special compression technologies and helps in making browsing faster. Carrying with my obsession for looking at ASNs and IP address, I enabled it again and visited bgp.he.net and was surprised to see the result.
I have been to quite a few countries but I must say Japan just stands out in internet connectivity. Overall connectivity is just amazing out here. As I landed on airport in Fukuoka, I noticed open free wifi (just one signup online form to accept TOS and it was up), later I noticed Fukuoka City Wifi project and it’s really visible across streets and very much works. As
I got to hotel, I was given SSID for wifi and it was just up! No crazy proxy, no crazy use of hotel room numbers/last name combinations. I was getting 20Mbps speed on wifi. This was a clear sign that transit was not bottleneck and likely wifi/end point connectivity was the one which was putting it on to 20Mbps (802.11n on a good quality router with 5Ghz). As I connected my laptop on wired LAN, I noticed (which I did expected by now) - connection synced at 100Mbps LAN and that was pretty much internet speed I was getting.