1IRTT-SERVER(1) IRTT Manual IRTT-SERVER(1)
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6 irtt-server - Isochronous Round-Trip Time Server
7
9 irtt server [args]
10
12 irtt server is the server for irtt(1).
13
15 -b addresses
16 Bind addresses (default “:2112”), comma separated list of:
17 Format Address Type
19 ─────────────────────────────────────────
20 :port unspecified address with
21 port, use with care
22 host host with default port
23 2112, see Host formats be‐
24 low
25 host:port host with specified port,
26 see Host formats below
27 %iface all addresses on interface
28 iface with default port
29 2112
30 %iface:port all addresses on interface
31 iface with port
32 Note: iface strings may contain * to match multiple interfaces
34 -d duration
36 Max test duration, or 0 for no maximum (default 0s, see Duration
37 units below)
38 -i interval
40 Min send interval, or 0 for no minimum (default 10ms, see Dura‐
41 tion units below)
42 -l length
44 Max packet length (default 0), or 0 for no maximum. Numbers
45 less than size of required headers will cause test packets to be
46 dropped.
47 --hmac=key
49 Add HMAC with key (0x for hex) to all packets, provides:
50 • Dropping of all packets without a correct HMAC
52 • Protection for server against unauthorized discovery and use
54 --syslog=uri
56 Log events to syslog (default don’t use syslog). URI format:
57 protocol://host:port/tag. Examples:
58 URI Result
60 ──────────────────────────────────────────────────────
61 local: Log to local syslog, de‐
62 fault tag irtt
63 local:/irttsrv Log to local syslog, tag
64 irttsrv
65 udp://logsrv:514/irttsrv UDP to logsrv:514, tag
68 irttsrv
69 tcp://logsrv:8514/ TCP to logsrv:8514, de‐
70 fault tag irtt
71 Note: not available on Windows, Plan 9 or Google Native Client
73 --timeout=duration
75 Timeout for closing connections if no requests received on a
76 connection (default 1m0s, see Duration units below). 0 means no
77 timeout (not recommended, especially on public servers). Max
78 client interval will be restricted to timeout/4.
79 --pburst=#
81 Packet burst allowed before enforcing minimum interval (default
82 5)
83 --fill=fill
85 Payload fill if not requested (default pattern:69727474). Pos‐
86 sible values include:
87 Value Fill
89 ────────────────────────────────────────
90 none Echo client payload (inse‐
91 cure on public servers)
92 rand Use random bytes from Go’s
93 math.rand
94 pattern:XX Use repeating pattern of
95 hex (default 69727474)
96 --allow-fills=fills
98 Comma separated patterns of fill requests to allow (default
99 rand). See options for –fill. Notes:
100 • Patterns may contain * for matching
102 • Allowing non-random fills insecure on public servers
104 • Use --allow-fills="" to disallow all fill requests
106 --tstamp=modes
108 Timestamp modes to allow (default dual). Possible values:
109 Value Allowed Timestamps
111 ────────────────────────────────────
112 none Don’t allow any timestamps
113 single Allow a single timestamp
114 (send, receive or mid‐
115 point)
116 dual Allow dual timestamps
117 --no-dscp
119 Don’t allow setting dscp (default false)
120 --set-src-ip
122 Set source IP address on all outgoing packets from listeners on
123 unspecified IP addresses (use for more reliable reply routing,
124 but increases per-packet heap allocations)
125 --thread
127 Lock request handling goroutines to OS threads
128 -h Show help
130 -v Show version
132 Host formats
134 Hosts may be either hostnames (for IPv4 or IPv6) or IP addresses. IPv6
135 addresses must be surrounded by brackets and may include a zone after
136 the % character. Examples:
137 Type Example
139 ──────────────────────────────────────
140 IPv4 IP 192.168.1.10
141 IPv6 IP [2001:db8:8f::2/32]
142 IPv4/6 hostname localhost
143 Note: IPv6 addresses must be quoted in most shells.
145 Duration units
147 Durations are a sequence of decimal numbers, each with optional frac‐
148 tion, and unit suffix, such as: “300ms”, “1m30s” or “2.5m”. Sanity not
149 enforced.
150 Suffix Unit
152 ──────────────────────
153 h hours
154 m minutes
155 s seconds
156 ms milliseconds
157 ns nanoseconds
158
160 Running an IRTT server that’s open to the outside world requires some
161 additional attention. For starters, the command line flags should be
162 used to, at a minimum:
163 • Restrict the duration (-d), interval (-i) and length (-l) of tests,
165 particularly for public servers
166 • Set an HMAC key (--hmac) for private servers to prevent unauthorized
168 discovery and use
169 In addition, there are various systemd(1) options available for secur‐
171 ing services. The irtt.service file included with the distribution
172 sets some commonly used options, but should not be considered exhaus‐
173 tive.
174 To secure a server for public use, additional steps may be taken that
176 are outside of the scope of this documentation, including but not lim‐
177 ited to:
178 • Installing irtt in an unprivileged container
180 • Setting up an iptables firewall (only UDP port 2112 must be open)
182 • Setting up a chroot jail
184 It should be noted that there are no known security vulnerabilities in
186 the Go language at this time, and the steps above, in particular the
187 chroot jail, may or may not serve to enhance security in any way. Go-
188 based servers are generally regarded as safe because of Go’s high-level
189 language constructs for memory management, and at this time IRTT makes
190 no use of Go’s unsafe (https://golang.org/pkg/unsafe/) package.
191
193 irtt server exits with one of the following status codes:
194 Code Meaning
196 ──────────────────────────────────
197 0 Success
198 1 Runtime error
200 2 Command line error
201 3 Two interrupt signals re‐
202 ceived
203
205 $ irtt server
206 Starts the server and listens on all addresses (unspecified ad‐
207 dress)
208 $ irtt server -d 30s -i 20ms -l 256 --fill=rand --allow-fills=""
210 Starts the server and listens on all addresses, setting the max‐
211 imum test duration to 30 seconds, minimum interval to 20 ms, and
212 maximum packet length to 256 bytes. Disallows fill requests and
213 forces all return packets to be filled with random data.
214 $ irtt server -b 192.168.100.11:64381 --hmac=secret
216 Starts the server and binds to IPv4 address 192.168.100.11, port
217 64381. Requires a valid HMAC on all packets with the key se‐
218 cret, otherwise packets are dropped.
219
221 irtt(1), irtt-client(1)
222 IRTT GitHub repository (https://github.com/heistp/irtt/)
224v0.9.0 February 11, 2018 IRTT-SERVER(1)