Differences between current version and predecessor to the previous major change of NetworkingNotes.
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Newer page: | version 3 | Last edited on Tuesday, September 20, 2005 3:39:34 pm | by JohnMcPherson | |
Older page: | version 2 | Last edited on Tuesday, October 12, 2004 1:12:45 am | by PerryLorier | Revert |
@@ -1,14 +1,53 @@
-This page discusses the difference in tuning networking on various OS's: http://foureleven.org:81/rosetta-stone-performance-tuning.html
-
See also NetworkingBestPractices
----
-!
!! Use of RFC:1918 addresses for routers
+!! Use of RFC:1918 addresses for routers
This has issues such as:
- [
[Host A] <-> [
[Router B] <-> [
[Router C] <-> [
[Router D] <-> [
[Router E] <-> [
[Host F ]]
+<verbatim>
+
[Host A] <-> [Router B] <-> [Router C] <-> [Router D] <-> [Router E] <-> [Host F ]
+</verbatim>
Now, Router B has a route to some RFC:1918 space (perhaps Host A is even on RFC:1918 behind [NAT]), Router D is numbered using RFC:1918 space (differently routable than Router B). Now, if the link from Router D and router E has a smaller [MTU] than the rest of the network, and Router B has reverse path filtering on, then A can no longer talk to F. If A traceroutes to F then it misses seeing D as well for the same reason.
RFC:1918 is evil and should be avoided at all costs, if you must use it, use it only on the edges on networks you control.
+
+!! IP Aliases
+Network interfaces can be assigned more than one [IP] address.
+
+Eg, to create aliases for the range 192.168.0.1 - 192.168.0.20:
+
+![FreeBSD]:
+<verbatim>
+for i in `jot 20 1` ;
+do
+ ifconfig fxp0 inet 192.168.0.$i alias ;
+done
+</verbatim>
+
+!Linux distros:
+(old way)%%%
+<verbatim>
+for i in `seq 1 20` ;
+do
+ ifconfig eth0:$i 192.168.0.$i ;
+done
+</verbatim>
+
+(new way)%%%
+<verbatim>
+for i in `seq 1 20` ;
+do
+ ip addr add 192.168.0.$i dev eth0 ;
+done
+</verbatim>
+This also lets you assign a range, eg:
+<verbatim>
+ ip addr add 192.168.0.0/24 dev eth0
+</verbatim>
+However, old tools like route(8) and ifconfig(8) won't show you anything added using this method.
+
+----
+!!!Other
+This page discusses the difference in tuning networking on various OS's: http://foureleven.org:81/rosetta-stone-performance-tuning.html
----
CategoryNetworking