Greetings Ondrej,

Thanks for your reply regarding this extended community.

I have tried the following two (2) configurations:
-------------------------------------------------
        bgp_ext_community.add((unknown 0x4004, 65300, 10000));
        bgp_ext_community.add((unknown 0x4004, 65300, 0x03E8));
-------------------------------------------------

In both cases, the neighbour Juniper router see the bandwidth as zero.
-------------------------------------------------
root@cache-router> show route 22.0.36.0/24 detail   

inet.0: 605 destinations, 1120 routes (604 active, 0 holddown, 1 hidden)
22.0.36.0/24 (2 entries, 1 announced)
        *BGP    Preference: 170/-101
                Next hop type: Indirect
                Address: 0x290c0e8
                Next-hop reference count: 514
                Source: 10.1.0.2
                Next hop type: Router, Next hop index: 635
                Next hop: 10.0.0.2 via xe-1/0/0.10, selected
                Session Id: 0x1
                Next hop type: Router, Next hop index: 724
                Next hop: 10.0.1.2 via xe-1/2/0.10
                Session Id: 0x5
                Protocol next hop: 10.0.0.2
                Indirect next hop: 0x2930410 1048576 INH Session ID: 0xbc9
                Protocol next hop: 10.0.1.2
                Indirect next hop: 0x2930c30 1048578 INH Session ID: 0x96
                State: <Active Int Ext>
                Peer AS: 65300
                Age: 6:20       Metric2: 0
                Validation State: unverified
                Task: BGP_65300_65300.10.1.0.2+40014
                Announcement bits (3): 0-KRT 4-Resolve tree 2 6-RT
                AS path: 65301 I
                AS path: Recorded
                Communities: bandwidth:65300:0.                                                 <-------------------- Bandwidth is zero???
                Accepted Multipath
                Localpref: 100
                Router ID: 10.1.0.2
         BGP    Preference: 170/-101
                Next hop type: Indirect
                Address: 0x28a58b4
                Next-hop reference count: 385
                Source: 10.1.0.6
                Next hop type: Router, Next hop index: 724
                Next hop: 10.0.1.2 via xe-1/2/0.10, selected
                Session Id: 0x5
                Protocol next hop: 10.0.1.2
                Indirect next hop: 0x2930c30 1048578 INH Session ID: 0x96
                State: <NotBest Int Ext>
                Inactive reason: Not Best in its group - Router ID
                Peer AS: 65300
                Age: 2d 3:37:52         Metric2: 0
                Validation State: unverified
                Task: BGP_65300_65300.10.1.0.6+36217
                AS path: 65301 I
                AS path: Recorded
                Accepted MultipathContrib
                Localpref: 100
                Router ID: 10.1.0.6
-------------------------------------------------

Here I've exported the wireshark decoding, where you can also see the extended community seems to be something strange:
-------------------------------------------------
No.     Time        Source                Destination           Protocol Length Info
    243 11.291591   10.1.0.2              10.1.0.1              BGP      543    UPDATE Message

Frame 243: 543 bytes on wire (4344 bits), 543 bytes captured (4344 bits)
Ethernet II, Src: RealtekU_31:8e:27 (52:54:00:31:8e:27), Dst: JuniperN_96:da:bd (10:0e:7e:96:da:bd)
802.1Q Virtual LAN, PRI: 0, CFI: 0, ID: 100
Internet Protocol Version 4, Src: 10.1.0.2 (10.1.0.2), Dst: 10.1.0.1 (10.1.0.1)
Transmission Control Protocol, Src Port: 40014 (40014), Dst Port: 179 (179), Seq: 1830, Ack: 378, Len: 473
[2 Reassembled TCP Segments (317 bytes): #241(161), #243(156)]
    [Frame: 241, payload: 0-160 (161 bytes)]
    [Frame: 243, payload: 161-316 (156 bytes)]
    [Segment count: 2]
    [Reassembled TCP length: 317]
    [Reassembled TCP Data: ffffffffffffffffffffffffffffffff013d020000002640...]
Border Gateway Protocol - UPDATE Message
    Marker: ffffffffffffffffffffffffffffffff
    Length: 317
    Type: UPDATE Message (2)
    Withdrawn Routes Length: 0
    Total Path Attribute Length: 38
    Path attributes
        Path Attribut - ORIGIN: IGP
            Flags: 0x40: Well-known, Transitive, Complete
            Type Code: ORIGIN (1)
            Length: 1
            Origin: IGP (0)
        Path Attribut - AS_PATH: 65301
            Flags: 0x40: Well-known, Transitive, Complete
            Type Code: AS_PATH (2)
            Length: 6
            AS Path segment: 65301
        Path Attribut - NEXT_HOP: 10.0.0.2
            Flags: 0x40: Well-known, Transitive, Complete
            Type Code: NEXT_HOP (3)
            Length: 4
            Next hop: 10.0.0.2 (10.0.0.2)
        Path Attribut - LOCAL_PREF: 100
            Flags: 0x40: Well-known, Transitive, Complete
            Type Code: LOCAL_PREF (5)
            Length: 4
            Local preference: 100
        Path Attribut - EXTENDED_COMMUNITIES
            Flags: 0xe0: Optional, Transitive, Partial
            Type Code: EXTENDED_COMMUNITIES (16)
            Length: 8
            Carried extended communities: (1 community)
                Community: ASN 65300, 0.000 Mbps
                    Community type high: Non-Transitive Two-Octet AS (0x40)
                    Subtype non-transitive as2: Link Bandwidth (0x04)
                    Two octets AS specific: 65300
                    Link bandwidth: 1.4013e-41                                                                      <-------------------- What the?
    Network Layer Reachability Information (NLRI)
Border Gateway Protocol - UPDATE Message
    Marker: ffffffffffffffffffffffffffffffff
    Length: 317
    Type: UPDATE Message (2)
    Withdrawn Routes Length: 0
    Total Path Attribute Length: 38
    Path attributes
        Path Attribut - ORIGIN: IGP
            Flags: 0x40: Well-known, Transitive, Complete
            Type Code: ORIGIN (1)
            Length: 1
            Origin: IGP (0)
        Path Attribut - AS_PATH: 65302
            Flags: 0x40: Well-known, Transitive, Complete
            Type Code: AS_PATH (2)
            Length: 6
            AS Path segment: 65302
        Path Attribut - NEXT_HOP: 10.0.0.26
            Flags: 0x40: Well-known, Transitive, Complete
            Type Code: NEXT_HOP (3)
            Length: 4
            Next hop: 10.0.0.26 (10.0.0.26)
        Path Attribut - LOCAL_PREF: 100
            Flags: 0x40: Well-known, Transitive, Complete
            Type Code: LOCAL_PREF (5)
            Length: 4
            Local preference: 100
        Path Attribut - EXTENDED_COMMUNITIES
            Flags: 0xe0: Optional, Transitive, Partial
            Type Code: EXTENDED_COMMUNITIES (16)
            Length: 8
            Carried extended communities: (1 community)
                Community: ASN 65300, 0.000 Mbps
                    Community type high: Non-Transitive Two-Octet AS (0x40)
                    Subtype non-transitive as2: Link Bandwidth (0x04)
                    Two octets AS specific: 65300
                    Link bandwidth: 1.4013e-41                                                         <-------------------- What the?
    Network Layer Reachability Information (NLRI)
-------------------------------------------------

Here is the decoded update message from the Juniper with the working community:
---------------------------------
No.     Time        Source                Destination           Protocol Length Info
     76 3.737018    10.1.0.1              10.1.0.2              BGP      417    UPDATE Message, UPDATE Message, UPDATE Message

Frame 76: 417 bytes on wire (3336 bits), 417 bytes captured (3336 bits)
Ethernet II, Src: JuniperN_96:da:bd (10:0e:7e:96:da:bd), Dst: RealtekU_31:8e:27 (52:54:00:31:8e:27)
Internet Protocol Version 4, Src: 10.1.0.1 (10.1.0.1), Dst: 10.1.0.2 (10.1.0.2)
Transmission Control Protocol, Src Port: 179 (179), Dst Port: 38333 (38333), Seq: 87, Ack: 69, Len: 351
Border Gateway Protocol - UPDATE Message
    Marker: ffffffffffffffffffffffffffffffff
    Length: 60
    Type: UPDATE Message (2)
    Withdrawn Routes Length: 0
    Total Path Attribute Length: 32
    Path attributes
        Path Attribut - ORIGIN: IGP
            Flags: 0x40: Well-known, Transitive, Complete
            Type Code: ORIGIN (1)
            Length: 1
            Origin: IGP (0)
        Path Attribut - AS_PATH: empty
            Flags: 0x40: Well-known, Transitive, Complete
            Type Code: AS_PATH (2)
            Length: 0
        Path Attribut - NEXT_HOP: 10.1.0.1
            Flags: 0x40: Well-known, Transitive, Complete
            Type Code: NEXT_HOP (3)
            Length: 4
            Next hop: 10.1.0.1 (10.1.0.1)
        Path Attribut - LOCAL_PREF: 100
            Flags: 0x40: Well-known, Transitive, Complete
            Type Code: LOCAL_PREF (5)
            Length: 4
            Local preference: 100
        Path Attribut - EXTENDED_COMMUNITIES
            Flags: 0xc0: Optional, Transitive, Complete
            Type Code: EXTENDED_COMMUNITIES (16)
            Length: 8
            Carried extended communities: (1 community)
                Community Transitive Two-Octet AS Unknown: 13414:1176255488
                    Community type high: Transitive Two-Octet AS (0x00)
                    Subtype as2: Unknown (0x04)
                    Two octets AS specific: 13414
                    Four octets AN specific: 1176255488                                                    <--------------------- Bandwidth set here
    Network Layer Reachability Information (NLRI)
        9.9.9.9/32
            NLRI prefix length: 32
            NLRI prefix: 9.9.9.9 (9.9.9.9)
Border Gateway Protocol - UPDATE Message
    Marker: ffffffffffffffffffffffffffffffff
    Length: 268
    Type: UPDATE Message (2)
    Withdrawn Routes Length: 0
    Total Path Attribute Length: 21
    Path attributes
        Path Attribut - ORIGIN: IGP
            Flags: 0x40: Well-known, Transitive, Complete
            Type Code: ORIGIN (1)
            Length: 1
            Origin: IGP (0)
        Path Attribut - AS_PATH: empty
            Flags: 0x40: Well-known, Transitive, Complete
            Type Code: AS_PATH (2)
            Length: 0
        Path Attribut - NEXT_HOP: 10.1.0.1
            Flags: 0x40: Well-known, Transitive, Complete
            Type Code: NEXT_HOP (3)
            Length: 4
            Next hop: 10.1.0.1 (10.1.0.1)
        Path Attribut - LOCAL_PREF: 100
            Flags: 0x40: Well-known, Transitive, Complete
            Type Code: LOCAL_PREF (5)
            Length: 4
            Local preference: 100
    Network Layer Reachability Information (NLRI)
        172.24.248.0/24
            NLRI prefix length: 24
            NLRI prefix: 172.24.248.0 (172.24.248.0)
        10.0.0.0/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.0.0 (10.0.0.0)
        10.0.0.4/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.0.4 (10.0.0.4)
        10.0.0.8/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.0.8 (10.0.0.8)
        10.0.0.12/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.0.12 (10.0.0.12)
        10.0.0.16/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.0.16 (10.0.0.16)
        10.0.0.20/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.0.20 (10.0.0.20)
        10.0.0.24/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.0.24 (10.0.0.24)
        10.0.0.28/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.0.28 (10.0.0.28)
        10.0.0.32/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.0.32 (10.0.0.32)
        10.0.0.36/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.0.36 (10.0.0.36)
        10.0.0.40/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.0.40 (10.0.0.40)
        10.0.0.44/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.0.44 (10.0.0.44)
        10.0.0.48/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.0.48 (10.0.0.48)
        10.0.0.52/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.0.52 (10.0.0.52)
        10.0.0.56/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.0.56 (10.0.0.56)
        10.0.0.60/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.0.60 (10.0.0.60)
        10.0.0.64/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.0.64 (10.0.0.64)
        10.0.0.68/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.0.68 (10.0.0.68)
        10.0.0.72/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.0.72 (10.0.0.72)
        10.0.0.76/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.0.76 (10.0.0.76)
        10.0.0.80/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.0.80 (10.0.0.80)
        10.1.0.0/30
            NLRI prefix length: 30
            NLRI prefix: 10.1.0.0 (10.1.0.0)
        10.0.1.0/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.1.0 (10.0.1.0)
        10.0.1.4/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.1.4 (10.0.1.4)
        10.0.1.8/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.1.8 (10.0.1.8)
        10.0.1.12/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.1.12 (10.0.1.12)
        10.0.1.16/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.1.16 (10.0.1.16)
        10.0.1.20/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.1.20 (10.0.1.20)
        10.0.1.24/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.1.24 (10.0.1.24)
        10.0.1.28/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.1.28 (10.0.1.28)
        10.0.1.32/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.1.32 (10.0.1.32)
        10.0.1.36/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.1.36 (10.0.1.36)
        10.0.1.40/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.1.40 (10.0.1.40)
        10.0.1.44/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.1.44 (10.0.1.44)
        10.0.1.48/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.1.48 (10.0.1.48)
        10.0.1.52/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.1.52 (10.0.1.52)
        10.0.1.56/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.1.56 (10.0.1.56)
        10.0.1.60/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.1.60 (10.0.1.60)
        10.0.1.64/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.1.64 (10.0.1.64)
        10.0.1.68/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.1.68 (10.0.1.68)
        10.0.1.72/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.1.72 (10.0.1.72)
        10.0.1.76/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.1.76 (10.0.1.76)
        10.0.1.80/30
            NLRI prefix length: 30
            NLRI prefix: 10.0.1.80 (10.0.1.80)
        10.1.0.4/30
            NLRI prefix length: 30
            NLRI prefix: 10.1.0.4 (10.1.0.4)
Border Gateway Protocol - UPDATE Message
    Marker: ffffffffffffffffffffffffffffffff
    Length: 23
    Type: UPDATE Message (2)
    Withdrawn Routes Length: 0
    Total Path Attribute Length: 0
---------------------------------


Kind regards,
Dave

On Mon, Dec 29, 2014 at 5:36 AM, Ondrej Zajicek <santiago@crfreenet.org> wrote:
On Tue, Dec 23, 2014 at 05:44:01PM -0800, dave seddon wrote:
> Greetings,
>
> Sorry for the dumb question, but I'm trying to work out how to set the
> extended communities.  Anybody know how to set the Link Bandwidth Extended
> communities?
...

> Basically, need to set the community to:
> "
>    This document defines a specific application of the two-octet AS
>    specific extended community.  IANA is requested to assign a sub- type
>    value of 0x04 for the link bandwidth extended community.
>
>
>       Name                                           Value
>       ----                                           -----
>       non-transitive Link Bandwidth Ext. Community  0x4004
> "
...
> e.g.
> export filter { bgp_ext_community.add((4, 65300, 999)); accept; };
> ( Mostly stolen from this nice example:
> http://bird.mpls.in/projects/mpls-bird/wiki/Bird_pe/2 )

Hi

Don't know if you use plain BIRD or one from bird.mpls.in, but "(4, 65300,
999)" is an invalid syntax. you should use: "(unknown 0x4004, 65300, 999)",
which works for me (not tested in tcpdump, but at least i got the same
back in show route).

--
Elen sila lumenn' omentielvo

Ondrej 'Santiago' Zajicek (email: santiago@crfreenet.org)
OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net)
"To err is human -- to blame it on a computer is even more so."