README.iproute2+tc

   1 iproute2+tc*
   2
   3 It's the first release of Linux traffic control engine.
   4
   5
   6 NOTES.
   7 * csz scheduler is inoperational at the moment, and probably
   8   never will be repaired but replaced with h-pfq scheduler.
   9 * To use "fw" classifier you will need ipfwchains patch.
  10 * No manual available. Ask me, if you have problems (only try to guess
  11   answer yourself at first 8)).
  12
  13
  14 Micro-manual how to start it the first time
  15 -------------------------------------------
  16
  17 A. Attach CBQ to eth1:
  18
  19 tc qdisc add dev eth1 root handle 1: cbq bandwidth 10Mbit allot 1514 cell 8 \
  20 avpkt 1000 mpu 64
  21
  22 B. Add root class:
  23
  24 tc class add dev eth1 parent 1:0 classid 1:1 cbq bandwidth 10Mbit rate 10Mbit \
  25 allot 1514 cell 8 weight 1Mbit prio 8 maxburst 20 avpkt 1000
  26
  27 C. Add default interactive class:
  28
  29 tc class add dev eth1 parent 1:1 classid 1:2 cbq bandwidth 10Mbit rate 1Mbit \
  30 allot 1514 cell 8 weight 100Kbit prio 3 maxburst 20 avpkt 1000 split 1:0 \
  31 defmap c0
  32
  33 D. Add default class:
  34
  35 tc class add dev eth1 parent 1:1 classid 1:3 cbq bandwidth 10Mbit rate 8Mbit \
  36 allot 1514 cell 8 weight 800Kbit prio 7 maxburst 20 avpkt 1000 split 1:0 \
  37 defmap 3f
  38
  39 etc. etc. etc. Well, it is enough to start 8) The rest can be guessed 8)
  40 Look also at more elaborated example, ready to start rsvpd,
  41 in rsvp/cbqinit.eth1.
  42
  43
  44 Terminology and advices about setting CBQ parameters may be found in Sally Floyd
  45 papers.
  46
  47
  48 Pairs X:Y are class handles, X:0 are qdisc handles.
  49 weight should be proportional to rate for leaf classes
  50 (I repeated it ten times less, but it is not necessary)
  51
  52 defmap is bitmap of logical priorities served by this class.
  53
  54 E. Another qdiscs are simpler. F.e. let's join TBF on class 1:2
  55
  56 tc qdisc add dev eth1 parent 1:2 tbf rate 64Kbit buffer 5Kb/8 limit 10Kb
  57
  58 F. Look at all that we created:
  59
  60 tc qdisc ls dev eth1
  61 tc class ls dev eth1
  62
  63 G. Install "route" classifier on root of cbq and map destination from realm
  64 1 to class 1:2
  65
  66 tc filter add dev eth1 parent 1:0 protocol ip prio 100 route to 1 classid 1:2
  67
  68 H. Assign routes to 10.11.12.0/24 to realm 1
  69
  70 ip route add 10.11.12.0/24 dev eth1 via whatever realm 1
  71
  72 etc. The same thing can be made with rules.
  73 I still did not test ipchains, but they should work too.
  74
  75
  76 Setup and code example of BPF classifier and action can be found under
  77 examples/bpf/, which should explain everything for getting started.
  78
  79
  80 Setup of rsvp and u32 classifiers is more hairy.
  81 If you read RSVP specs, you will understand how rsvp classifier
  82 works easily. What's about u32... That's example:
  83
  84
  85 #! /bin/sh
  86
  87 TC=/home/root/tc
  88
  89 # Setup classifier root on eth1 root (it is cbq)
  90 $TC filter add dev eth1 parent 1:0 prio 5 protocol ip u32
  91
  92 # Create hash table of 256 slots with ID 1:
  93 $TC filter add dev eth1 parent 1:0 prio 5 handle 1: u32 divisor 256
  94
  95 # Add to 6th slot of hash table rule to select tcp/telnet to 193.233.7.75
  96 # direct it to class 1:4 and prescribe to fall to best effort,
  97 # if traffic violate TBF (32kbit,5K)
  98 $TC filter add dev eth1 parent 1:0 prio 5 u32 ht 1:6: \
  99         match ip dst 193.233.7.75 \
 100         match tcp dst 0x17 0xffff \
 101         flowid 1:4 \
 102         police rate 32kbit buffer 5kb/8 mpu 64 mtu 1514 index 1
 103
 104 # Add to 1th slot of hash table rule to select icmp to 193.233.7.75
 105 # direct it to class 1:4 and prescribe to fall to best effort,
 106 # if traffic violate TBF (10kbit,5K)
 107 $TC filter add dev eth1 parent 1:0 prio 5 u32 ht 1:: \
 108         sample ip protocol 1 0xff \
 109         match ip dst 193.233.7.75 \
 110         flowid 1:4 \
 111         police rate 10kbit buffer 5kb/8 mpu 64 mtu 1514 index 2
 112
 113 # Lookup hash table, if it is not fragmented frame
 114 # Use protocol as hash key
 115 $TC filter add dev eth1 parent 1:0 prio 5 handle ::1 u32 ht 800:: \
 116         match ip nofrag \
 117         offset mask 0x0F00 shift 6 \
 118         hashkey mask 0x00ff0000 at 8 \
 119         link 1:
 120
 121
 122 Alexey Kuznetsov
 123 kuznet@ms2.inr.ac.ru