P
PacketLife
packetlife.net · Personal blog · on HN since 2008
Jeremy Stretch's networking blog, with protocol explanations, cheat sheets, and notes on TCP, BGP, and network gear.
What HN saysHN commenters recommend its networking cheat sheets and cite its TCP selective acknowledgment post for lossy links and its RIPE 1.0.0.0/8 post.
28HN people shared it
13linked it in comments
16stories submitted
107story points
3 years agolast shared
2008people per year2026
Most-shared posts
- 1Networking cheat sheets4 people · 10 points · first shared 2016 · discussion on HN
- 2TCP Slow Start2 people · 4 points · first shared 2012 · discussion on HN
- 3Tcp selective acknowledgments sack2 people · first shared 2014
- 4Ripe plays with 1 0 0 0 network apnic allocation2 people · first shared 2018
- 5Cumulus Linux – first impressions1 people · 51 points · first shared 2014 · 27 comments on HN
- 6FAQ: Being a network admin in Iraq1 people · 23 points · first shared 2008 · 11 comments on HN
- 7Announcing Netbox (from Digital Ocean)1 people · 4 points · first shared 2016 · 1 comments on HN
- 8Common Ports Cheat Sheet (including Malware Ports) [pdf]1 people · 2 points · first shared 2016 · discussion on HN
- 9Networking Cheatsheets1 people · 2 points · first shared 2008 · discussion on HN
- 10IETF working on IPv4.1 as alternative to IPv61 people · 2 points · first shared 2011 · 5 comments on HN
- 11Why network neutrality is a big deal1 people · 2 points · first shared 2009 · discussion on HN
- 12Modifying the BGP Path Selection Process on iOS (2010)1 people · 2 points · first shared 2022 · discussion on HN
- 13Markdown Cheat sheet.1 people · 1 points · first shared 2008 · discussion on HN
- 14Observations on Seven Years of Maintaining Open Source1 people · 1 points · first shared 2023 · discussion on HN
- 15Intro to Scapy, a framework for crafting and transmitting arbitrary packets.1 people · 1 points · first shared 2011 · discussion on HN
What HN people wrote when they linked it
jlgaddis · 2020-03-15
Many years ago, Jeremy Stretch created a series of (networking-centric) "cheat sheets" [0] which may be of interest.
As boring as they can be to read, the RFCs are still the best single reference WRT network protocols and such.
---
[0]: https://packetlife.net/library/cheat-sheets/
xiconfjs · 2023-11-07
You could check if you have SACKs [1] enabled - these can help by a lot on lossy uplinks using tcp.
[1] https://packetlife.net/blog/2010/jun/17/tcp-selective-acknowledgments-…
tyingq · 2021-04-28
https://packetlife.net/library/cheat-sheets/
It's also fairly easy to make a nice poster from a patent by mixing snippets of titles, claims, and diagrams.
milkmiruku · 2018-04-06
Previously (February 2010);
"As part of an effort to de-bogonise this newly allocated address space, RIPE, in cooperation with APNIC, made some test advertisements to the global BGP table for several prefixes with 1.0.0.0/8. Specifically, these networks included 1.1.1.0/24 and 1.2.3.0/24. Why these networks? Because they contain the novel (and illegal) IPv4 addresses 1.1.1.1 and 1.2.3.4, of course.
"Shortly after announcing the routes to the world, RIPE's RIS was flooded with over 50 Mbps of traffic destined for what is still an unallocated network; it should not appear on the global Internet."
* http://packetlife.net/blog/2010/feb/5/ripe-plays-with-1-0-0-0-network-…
chris_wot · 2016-05-03
Well that's just dandy. They are plagiarising.
http://packetlife.net/blog/2016/mar/9/dont-be-discouraged-plagiarists/
All those PDFs that they have taken without permission and stored in their GitHub repository are the giveaway:
https://github.com/overthecs/overthecs.github.io/tree/master/static/cs
ju-st · 2015-09-23
The problem with this is that you will get X million "new" IP addresses. But in Y years you will have the same problems as we have now again, because the X million IPs are again consumed.
So it is much better to focus on the implementation of IPv6.
The E block is a lost cause: http://packetlife.net/blog/2010/oct/14/ipv4-exhaustion-what-about-clas…
fjarlq · 2014-12-22
That's the slow start algorithm, part of standard TCP congestion avoidance:
http://packetlife.net/blog/2011/jul/5/tcp-slow-start/
Sami_Lehtinen · 2014-08-13
There's no reason to ACK every packet. It's very common to deal with things selectively. SACK: http://packetlife.net/blog/2010/jun/17/tcp-selective-acknowledgments-s…
mburns · 2014-08-12
NANOG[0] warned about it in May, and there is a blog post [1] that expands on the risk. Cisco 6500/7600 (if they are set to hold the complete BGP table) are known to be affected.
[0] http://mailman.nanog.org/pipermail/nanog/2014-May/066880.html
[1] http://packetlife.net/blog/2014/may/6/global-ipv4-routing-table-hits-5…
shivam14 · 2010-04-01
Cisco IOS QoS configuration guide - flesh tone recognition to classify and monitor suspect pornographic images
http://packetlife.net/media/blog/attachments/413/nbar_flesh_tone.html
rixrax · 2019-11-03
I wish they had at least made an effort to link to RFCs[0][1][2][3][...] that define SSH2 protocol and that also explain the handshake portion more accurately and in more detail (found one link to rfc4253 from article).
I also hope they didn't decide to roll their own SSH2 stack for their product (article doesn't mention if they did or did not).
Another thing I wish people would do is to include a link to .pcap of the network traffic they are trying to explain. Found one[pcap].
[0] https://tools.ietf.org/html/rfc4251
[1] https://tools.ietf.org/html/rfc4252
[2] https://tools.ietf.org/html/rfc4253
[3] https://tools.ietf.org/html/rfc4254
[...] https://tools.ietf.org/html/rfc4250 (and others)
[pcap] https://packetlife.net/captures/protocol/ssh/