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bgp-bgpq4/bgpq3.txt

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minor change: -m <max> option allows to ignore 'too long prefixes' registered in some IRRs. documentation redesigned.
2012-05-18 15:52:06 +00:00
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NAME
----
`bgpq3` - bgp filtering automation for Cisco and Juniper routers
SYNOPSIS
--------
bgpq3 [-h host] [-S sources] [-EP] [-f asn | -G asn] [-36ADd] [-R len] [-m max] OBJECTS [...]
DESCRIPTION
-----------
The bgpq3 utility used to generate Cisco and Juniper prefix-lists,
extended access-lists, policy-statement terms and as-path lists based on
RADB data.
The options are as follows:
- -3
> assume that your device is asn32-capable.
- -6
> generate IPv6 prefix/access-lists (IPv4 by default).
- -A
> try to aggregate generated filters as much as possible (Cisco
prefix-lists and Juniper route-filters only supported).
- -d
> enable some debugging output.
- -D
> use asdot notation for Cisco as-path access-lists.
- -E
> generate extended access-list (Cisco) or policy-statement term using
route-filters (Juniper).
- -f number
> generate input as-path access-list.
- -G number
> generate output as-path access-list.
- -h host
> host running IRRD database (default: whois.radb.net)
- -J
> generate config for Juniper (Cisco by default).
- -m len
> maximum length of accepted prefixes
- -M match
> extra match conditions for Juniper route-filters.
- -l name
> name of generated entry.
- -P
> generate prefix-list (default behaviour, flag added for backward
compatibility only).
- -R len
> allow more-specific routes up to specified masklen too.
(Please, note: objects with prefix-length greater than specified length
will be always allowed.)
- -S sources
> use specified sources only (default: RADB,RIPE,APNIC).
- -T
> disable pipelining.
- -X
> generate config for Cisco IOS XR devices (plain IOS by default).
`OBJECTS` means networks (in prefix format), autonomous systems and as-macros.
EXAMPLES
--------
Generating named Juniper prefix-filter for `AS20597`:
user@host:~>bgpq3 -Jl eltel AS20597
policy-options {
replace:
prefix-list eltel {
81.9.0.0/20;
81.9.32.0/20;
81.9.96.0/20;
81.222.128.0/20;
81.222.192.0/18;
85.249.8.0/21;
85.249.224.0/19;
89.112.0.0/19;
89.112.4.0/22;
89.112.32.0/19;
89.112.64.0/19;
217.170.64.0/20;
217.170.80.0/20;
}
}
For Cisco we can use aggregation (-A) flag to make this prefix-filter
more compact:
user@host:~>bgpq3 -Al eltel AS20597
no ip prefix-list eltel
ip prefix-list eltel permit 81.9.0.0/20
ip prefix-list eltel permit 81.9.32.0/20
ip prefix-list eltel permit 81.9.96.0/20
ip prefix-list eltel permit 81.222.128.0/20
ip prefix-list eltel permit 81.222.192.0/18
ip prefix-list eltel permit 85.249.8.0/21
ip prefix-list eltel permit 85.249.224.0/19
ip prefix-list eltel permit 89.112.0.0/18 ge 19 le 19
ip prefix-list eltel permit 89.112.4.0/22
ip prefix-list eltel permit 89.112.64.0/19
ip prefix-list eltel permit 217.170.64.0/19 ge 20 le 20
and, as you see, prefixes `89.112.32.0/19` and `89.112.64.0/19` now aggregated
into single entry
ip prefix-list eltel permit 89.112.0.0/18 ge 19 le 19.
Well, for Juniper we can generate even more interesting policy-statement,
using `-M <extra match conditions>`, `-R <len>` and hierarchical names:
user@host:~>bgpq3 -AJEl eltel/specifics -R 32 -M "community blackhole" AS20597
policy-options {
policy-statement eltel {
term specifics {
replace:
from {
community blackhole;
route-filter 81.9.0.0/20 upto /32;
route-filter 81.9.32.0/20 upto /32;
route-filter 81.9.96.0/20 upto /32;
route-filter 81.222.128.0/20 upto /32;
route-filter 81.222.192.0/18 upto /32;
route-filter 85.249.8.0/21 upto /32;
route-filter 85.249.224.0/19 upto /32;
route-filter 89.112.0.0/18 prefix-length-range /19-/32;
route-filter 89.112.64.0/19 upto /32;
route-filter 217.170.64.0/19 prefix-length-range /20-/32;
}
}
}
}
generated policy-option term now allows all more-specific routes
for eltel networks if they marked with community 'blackhole' (defined
elsewhere in configuration).
Of course, `bgpq3` supports IPv6 (-6):
user@host:~>bgpq3 -6l as-retn-6 AS-RETN6
no ipv6 prefix-list as-retn-6
ipv6 prefix-list as-retn-6 permit 2001:7fb:fe00::/48
ipv6 prefix-list as-retn-6 permit 2001:7fb:fe01::/48
[....]
and ASN32
user@host:~>bgpq3 -J3f 112 AS-SPACENET
policy-options {
replace:
as-path-group NN {
as-path a0 "^112(112)*$";
as-path a1 "^112(.)*(1898|5539|8495|8763|8878|12136|12931|15909)$";
as-path a2 "^112(.)*(21358|23456|23600|24151|25152|31529|34127|34906)$";
as-path a3 "^112(.)*(35052|41720|43628|44450|196611)$";
}
}
see `AS196611` in the end of the list ? That's `AS3.3` in 'asplain' notation.
If your router does not support ASN32 (yet) you should not use switch -3,
and the result will be next:
user@host:~>bgpq3 -f 112 AS-SPACENET
no ip as-path access-list NN
ip as-path access-list NN permit ^112( 112)*$
ip as-path access-list NN permit ^112( [0-9]+)* (1898|5539|8495|8763)$
ip as-path access-list NN permit ^112( [0-9]+)* (8878|12136|12931|15909)$
ip as-path access-list NN permit ^112( [0-9]+)* (21358|23456|23600|24151)$
ip as-path access-list NN permit ^112( [0-9]+)* (25152|31529|34127|34906)$
ip as-path access-list NN permit ^112( [0-9]+)* (35052|41720|43628|44450)$
`AS196611` is no more in the list, however, `AS23456` (transition AS) would
have been added to list if it were not present.
DIAGNOSTICS
-----------
When everything is OK, `bgpq3` generates result to standard output and
exits with status == 0. In case of errors they are printed to stderr and
program exits with non-zero status.
SEE ALSO
--------
1. [Routing Arbiter](http://www.radb.net/)
2. [draft-michaelson-4byte-as-representation-05.txt](http://www.ietf.org/internet-drafts/draft-michaelson-4byte-as-representation-05.txt)
for information on 'asdot' and 'asplain' notations.
3. [Cisco documentation](http://www.cisco.com/en/US/prod/collateral/iosswrel/ps6537/ps6554/ps6599/data_sheet_C78-521821.html)
for information on Cisco implementation of ASN32.
AUTHOR
------
Alexandre Snarskii [snar@snar.spb.ru](mailto:snar@snar.spb.ru)
Program Homepage
----------------
[http://snar.spb.ru/prog/bgpq3/](http://snar.spb.ru/prog/bgpq3/)
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