#Tcpreplay clone ##Overview This software is a cloned version of the original one, made for working with netmap (see http://info.iet.unipi.it/~luigi/netmap/ for more information about netmap). This software works in two different modes:
- Replay
- Pcap
##Replay In replay mode the user provides two different netmap interfaces. The software accepts all the incoming packets from one interface and retransmits them on the other one. This retransmission works in both direction.
##Pcap In this mode the user provides one interface and one capture file (.cap). The software replays the content of the file to the specified interface. In particular the software supports three different transmission timing: real, fixed bandwidth and maximum speed.
##Usage options Replay mode accepts the following options:
- B bandwidth in bps (only for replay mode)
- D delay in seconds (only for replay mode)
- Q qsize in bytes (both modes)
- L loss probability (only for replay mode)
- i interface name (two mandatory, see below for more details)
- v verbose (only for replay mode)
- b batch size (only for replay mode)
- m mode (only for pcap mode)
###Bandwidth If the -B option is used, tcpreplay transmits packets with the given bandwidth. Bandwidths are expressed in bits per second, can be followed by a character specifying a different unit e.g.
| b/B | bits per second |
| k/K | kbits/s (10^3 bits/s) |
| m/M | mbits/s (10^6 bits/s) |
| g/G | gbits/s (10^9 bits/s) |
Currently implemented options
| const,b | constant bw, excluding mac framing |
| ether,b | constant bw, including ethernet framing (20 bytes framing + 4 bytes crc) |
###Delay Specifiyng the delay options -D let the program randomly choose a sequence of values to be used as delays introduced at each packet. Times are in nanoseconds, can be followed by a character specifying a different unit e.g.
| n | nanoseconds |
| u | microseconds |
| m | milliseconds |
| s | seconds |
Currently implemented options:
| constant,t | constant delay equal to t |
| uniform,tmin,tmax | uniform delay between tmin and tmax |
| exp,tavg,tmin | exponential distribution with average tavg and minimum tmin (corresponds to an exponential distribution with argument 1/(tavg-tmin) ) |
###Queue size The -Q options set the queue size to the given value. If the user does not specify a queue size, 50k is used as default value. Sizes are in bytes, but suffixes can be used for different units e.g.
| k/K | kilobytes (1024 bytes) |
| m/M | megabytes (1024^2 bytes) |
| g/G | gigabytes (1024^3 bytes) |
###Loss probability The -L option sets a loss probability. Loss is expressed as packet or bit error rate, which is an absolute number between 0 and 1 (typically small). Currently implemented options
| plr,p | uniform packet loss rate p, independent of packet size |
| burst,p | burst loss with burst probability p and burst length uniformly distributed between lmin and lmax |
| ber,p | uniformly distributed bit error rate p, so actual loss prob. depends on size. |
###Interface The -i option specifies the interface to be used. Two interfaces are mandatory while operating in replay mode. On the other hand, in pcap mode, tcpreplay needs just a single output interface and a .cap source file.
###Verbose The -v option enables output of additiona informations during execution.
###Batch The -b option sets the burst size, if not used the default value is 1024. Valid range is between 1 and 8192.
###Transmission mode The -m option specifies the pcap transmission mode. Currently implemented options are
| real | packets are sent using times taken from pcap |
| fast | packets are sent as fast as possible |
| fixed,b | packets are sent with a fixed bandwidth b |
##Examples In replay mode, reads incoming traffic from eth0 and retransmits it on eth1
sudo ./tcpreplay -i netmap:eth0 -i netmap:eth1
In replay mode, reads incoming traffic from eth0 and retransmits it on eth1 with constant bandwidth 100k, connstant delay 1s and uniform loss probability 0.5
sudo ./tcpreplay -i netmap:eth0 -i netmap:eth1 -B const,100k -D const,1s -L
plr,0.5
In pcap mode, reads from a pcap file and retransmits on a port of the VALE switch with fast transmission mode
sudo ./tcpreplay -i file.cap -i vale:1 -m fast
In pcap mode, reads from a pcap file and retransmits on a pipe using the VALE switch with fixed transmission mode
sudo ./tcpreplay -i file.cap -i vale1:a\{1 -m fixed,100k
##Author This code is written by Luigi Rizzo, Andrea Beconcini, Francesco Mola and Lorenzo Biagini