1BGPQ4(8) BSD System Manager's Manual BGPQ4(8)
2
4 bgpq4 — bgp filtering automation tool
5
7 bgpq4 [-h host[:port]] [-S sources] [-EPz] [-f asn | -F fmt | -G asn -H
8 asn -t] [-46ABbDdJjNnpsXU] [-a asn] [-r len] [-R len] [-m max]
9 [-W len] OBJECTS [...] [EXCEPT OBJECTS]
10
12 The bgpq4 utility used to generate configurations (prefix-lists, extended
13 access-lists, policy-statement terms and as-path lists) based on IRR
14 data.
15 The options are as follows:
17 -4 generate IPv4 prefix/access-lists (default).
19 -6 generate IPv6 prefix/access-lists (IPv4 by default).
21 -A try to aggregate prefix-lists as much as possible (not all output
23 formats supported).
24 -a asn specify what asn shall be denied in case of empty prefix-list
26 (OpenBGPD)
27 -B generate output in OpenBGPD format (default: Cisco)
29 -b generate output in BIRD format (default: Cisco).
31 -d enable some debugging output.
33 -e generate output in Arista EOS format (default: Cisco).
35 -E generate extended access-list (Cisco), policy-statement term us‐
37 ing route-filters (Juniper), [ip|ipv6]-prefix-list (Nokia) or
38 prefix-sets (OpenBGPd).
39 -f number
41 generate input as-path access-list.
42 -F fmt generate output in user-defined format.
44 -G number
46 generate output as-path access-list.
47 -H number
49 generate output as-list for as-path-origin filter (JunOS 21.3R1+)
50 -h host[:port]
52 host running IRRD database (default: rr.ntt.net).
53 -J generate config for Juniper (default: Cisco).
55 -j generate output in JSON format (default: Cisco).
57 -K generate config for Mikrotik ROSv6 (default: Cisco).
59 -K7 generate config for Mikrotik ROSv7 (default: Cisco).
61 -l name
63 name of generated entry.
64 -L limit
66 limit recursion depth when expanding as-sets.
67 -m len maximum prefix-length of accepted prefixes (default: 32 for IPv4
69 and 128 for IPv6).
70 -M match
72 extra match conditions for Juniper route-filters.
73 -n generate config for Nokia SR OS MD-CLI (Cisco IOS by default)
75 -N generate config for Nokia SR OS classic CLI (Cisco IOS by de‐
77 fault).
78 -p emit prefixes where the origin ASN is in the private ASN range
80 (disabled by default).
81 -r len allow more specific routes starting with specified masklen too.
83 -R len allow more specific routes up to specified masklen too.
85 -s generate sequence numbers in IOS-style prefix-lists.
87 -S sources
89 use specified sources only (recommended: RPKI,AFRINIC,AP‐
90 NIC,ARIN,LACNIC,RIPE).
91 -t generate as-sets for OpenBGPd, BIRD and JSON formats.
93 -T disable pipelining (not recommended).
95 -U generate config for Huawei devices (Cisco IOS by default)
97 -u generate config for Huawei devices in XPL format (Cisco IOS by
99 default)
100 -W len generate as-path strings of no more than len items (use 0 for in‐
102 finity).
103 -X generate config for Cisco IOS XR devices (plain IOS by default).
105 -z generate route-filter-lists (JunOS 16.2+).
107 OBJECTS
109 means networks (in prefix format), autonomous systems, as-sets
110 and route-sets.
111 EXCEPT OBJECTS
113 those objects will be excluded from expansion.
114
116 Generating named juniper prefix-filter for AS20597:
117 $ bgpq4 -Jl eltel AS20597
119 policy-options {
120 replace:
121 prefix-list eltel {
122 81.9.0.0/20;
123 81.9.32.0/20;
124 81.9.96.0/20;
125 81.222.128.0/20;
126 81.222.192.0/18;
127 85.249.8.0/21;
128 85.249.224.0/19;
129 89.112.0.0/19;
130 89.112.4.0/22;
131 89.112.32.0/19;
132 89.112.64.0/19;
133 217.170.64.0/20;
134 217.170.80.0/20;
135 }
136 }
137 For Cisco we can use aggregation (-A) flag to make this prefix-filter
139 more compact:
140 $ bgpq4 -Al eltel AS20597
142 no ip prefix-list eltel
143 ip prefix-list eltel permit 81.9.0.0/20
144 ip prefix-list eltel permit 81.9.32.0/20
145 ip prefix-list eltel permit 81.9.96.0/20
146 ip prefix-list eltel permit 81.222.128.0/20
147 ip prefix-list eltel permit 81.222.192.0/18
148 ip prefix-list eltel permit 85.249.8.0/21
149 ip prefix-list eltel permit 85.249.224.0/19
150 ip prefix-list eltel permit 89.112.0.0/18 ge 19 le 19
151 ip prefix-list eltel permit 89.112.4.0/22
152 ip prefix-list eltel permit 89.112.64.0/19
153 ip prefix-list eltel permit 217.170.64.0/19 ge 20 le 20
154 Prefixes 89.112.0.0/19 and 89.112.32.0/19 now aggregated into single en‐
156 try 89.112.0.0/18 ge 19 le 19.
157 Well, for Juniper we can generate even more interesting policy-options,
159 using -M <extra match conditions>, -R <len> and hierarchical names:
160 $ bgpq4 -AJEl eltel/specifics -r 29 -R 32 -M "community blackhole" AS20597
162 policy-options {
163 policy-statement eltel {
164 term specifics {
165 replace:
166 from {
167 community blackhole;
168 route-filter 81.9.0.0/20 prefix-length-range /29-/32;
169 route-filter 81.9.32.0/20 prefix-length-range /29-/32;
170 route-filter 81.9.96.0/20 prefix-length-range /29-/32;
171 route-filter 81.222.128.0/20 prefix-length-range /29-/32;
172 route-filter 81.222.192.0/18 prefix-length-range /29-/32;
173 route-filter 85.249.8.0/21 prefix-length-range /29-/32;
174 route-filter 85.249.224.0/19 prefix-length-range /29-/32;
175 route-filter 89.112.0.0/17 prefix-length-range /29-/32;
176 route-filter 217.170.64.0/19 prefix-length-range /29-/32;
177 }
178 }
179 }
180 }
181 generated policy-option term now allows all specifics with prefix-length
182 between /29 and /32 for eltel networks if they match with special commu‐
183 nity blackhole (defined elsewhere in configuration).
184 Of course, this version supports IPv6 (-6):
186 $ bgpq4 -6l as-retn-6 AS-RETN6
188 no ipv6 prefix-list as-retn-6
189 ipv6 prefix-list as-retn-6 permit 2001:7fb:fe00::/48
190 ipv6 prefix-list as-retn-6 permit 2001:7fb:fe01::/48
191 [....]
192 and assumes your device supports 32-bit ASNs
193 $ bgpq4 -Jf 112 AS-SPACENET
195 policy-options {
196 replace:
197 as-path-group NN {
198 as-path a0 "^112(112)*$";
199 as-path a1 "^112(.)*(1898|5539|8495|8763|8878|12136|12931|15909)$";
200 as-path a2 "^112(.)*(21358|23456|23600|24151|25152|31529|34127|34906)$";
201 as-path a3 "^112(.)*(35052|41720|43628|44450|196611)$";
202 }
203 }
204 see `AS196611` in the end of the list ? That's a 32-bit ASN.
205
207 If you want to generate configuration not for routers, but for some other
208 programs/systems, you may use user-defined formatting, like in example
209 below:
210 $ bgpq4 -F "ipfw add pass all from %n/%l to any\n" as3254
212 ipfw add pass all from 62.244.0.0/18 to any
213 ipfw add pass all from 91.219.29.0/24 to any
214 ipfw add pass all from 91.219.30.0/24 to any
215 ipfw add pass all from 193.193.192.0/19 to any
216 Recognized format sequences are:
218 %n network
220 %l mask length
221 %a aggregate low mask length
222 %A aggregate high mask length
223 %N object name
224 %m object mask
225 %i inversed mask
226 \n new line
227 \t tabulation
228 Please note that no new lines are inserted automatically after each sen‐
230 tence. You have to add them into format string manually, otherwise the
231 output will be in one single line (sometimes it makes sense):
232 $ bgpq4 -6F "%n/%l; " as-eltel
234 2001:1b00::/32; 2620:4f:8000::/48; 2a04:bac0::/29; 2a05:3a80::/48;
235
237 By default bgpq4 trusts data from all the databases mirrored into NTT's
238 IRR service. Unfortunately, not all these databases are equal in how
239 much we can trust their data. RIR maintained databases (AFRINIC, ARIN,
240 APNIC, LACNIC and RIPE) shall be trusted more than the others because
241 they have the knowledge about who the rightful holders of resources are,
242 while other databases lack this knowledge and can (and, actually do) con‐
243 tain stale data: no one but the RIRs care to remove outdated route-ob‐
244 jects when address space is de-allocated or transferred. In order to
245 keep their filters both compact and actual, bgpq4 users are encouraged to
246 use '-S' flag to limit database sources to only the ones they trust.
247 General recommendations:
249 Use a minimal set of RIR databases (only those in which you and your cus‐
251 tomers have registered route-objects).
252 Avoid using ARIN-NONAUTH and RIPE-NONAUTH as trusted sources: these
254 records were created in the database, but for address space allocated to
255 different RIRs, so the NONAUTH databases have no chance to confirm valid‐
256 ity of the route objects they contain.
257 $ bgpq4 -S RIPE,RADB as-space
259 no ip prefix-list NN
260 ip prefix-list NN permit 195.190.32.0/19
261 $ bgpq4 -S RADB,RIPE as-space
263 no ip prefix-list NN
264 ip prefix-list NN permit 45.4.4.0/22
265 ip prefix-list NN permit 45.4.132.0/22
266 ip prefix-list NN permit 45.6.128.0/22
267 ip prefix-list NN permit 45.65.184.0/22
268 [...]
269
271 To improve `bgpq4` performance when expanding extra-large AS-SETs you
272 shall tune OS settings to enlarge TCP send buffer.
273 FreeBSD can be tuned in the following way:
275 sysctl -w net.inet.tcp.sendbuf_max=2097152
277 Linux can be tuned in the following way:
279 sysctl -w net.ipv4.tcp_window_scaling=1
281 sysctl -w net.core.rmem_max=2097152
282 sysctl -w net.core.wmem_max=2097152
283 sysctl -w net.ipv4.tcp_rmem="4096 87380 2097152"
284 sysctl -w net.ipv4.tcp_wmem="4096 65536 2097152"
285
287 This project uses autotools. If you are building from the repository, run
288 the following command to prepare the build system:
289 ./bootstrap
291 In order to compile the software, run:
293 ./configure
295 make
296 make install
297 If you wish to remove the generated build system files from your working
299 tree, run:
300 make maintainer-clean
302 In order to create a distribution archive, run:
304 make dist
306
308 When everything is OK, bgpq4 generates access-list to standard output and
309 exits with status == 0. In case of errors they are printed to stderr and
310 program exits with non-zero status.
311
313 Alexandre Snarskii, Christian David, Claudio Jeker, Job Snijders, Massim‐
314 iliano Stucchi, Michail Litvak, Peter Schoenmaker, Roelf Wichertjes, and
315 contributions from many others.
316
318 https://github.com/bgp/bgpq4 BGPQ4 on Github.
319 http://bgpfilterguide.nlnog.net/ NLNOG's BGP Filter Guide.
321 https://tcp0.com/cgi-bin/mailman/listinfo/bgpq4 Users and interested par‐
323 ties can subscribe to the BGPQ4 mailing list bgpq4@tcp0.com
324
326 Job Snijders <job@sobornost.net>
327BSD December 23, 2020 BSD