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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