Re: challenge of year: connect to LAN using wireless-ap over bridge + unmanaged l2tpv3 tunnel + bridge? it's possible?

You can't bridge 802.11 segments with normal ethernet segments. Wifi AP's
that do this use magic; or hidden pesudo bridges to do the same.

You will need to use something like relayd to form a psuedo bridge between
your wired and wireless segments or use routing.


-Joel


On 23 August 2013 14:21, Jorge Pereira <[email protected]> wrote:

> hi everyone,
>
>     so,first it seemed a trivial question to me, but since I could not
> find anybody being neither able to answer
> this question nor giving a short config example. after a few sleepless
> nights and exhausting all the reading
> and research. here I am sharing my problem with all of you, in the hope of
> some possible solution/sugestion.
> or is it that this is impossible??
>
> below my scheme/layout.
>
> +---------------------------------------------------------+
> | MAIN SERVER - 10.60.61.1 (DHCP SERVER) |
> +---------------------------------------------------------+
>                      |
> +---------------------------+
> |    NETWORK vlan601 |
> |  net 10.251.0.0/16      |
> |  gw:10.251.0.1            |
> +---------------------------+
>                     |
> +------------------------------------------------------------------+
>  | SERVER B (BRIDGE / unmanaged L2TPv3) - BAHIA |
> +------------------------------------------------------------------+
>
> *root@bahia:~# * ip -d addr show eth0 *# WAN*
> 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state
> UP qlen 1000
>     link/ether 00:50:56:a7:13:49 brd ff:ff:ff:ff:ff:ff
>     inet 200.243.1.5/24 brd 200.243.1.255 scope global eth0
>     inet6 fe80::250:56ff:fea7:1349/64 scope link
>        valid_lft forever preferred_lft forever
> *root@bahia:~# * ip -d addr show eth1 *# LAN (VLAN/TRUNK)*
> 3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state
> UP qlen 1000
>     link/ether 00:50:56:a7:13:4a brd ff:ff:ff:ff:ff:ff
>     inet6 fe80::250:56ff:fea7:134a/64 scope link
>        valid_lft forever preferred_lft forever
> *root@bahia:~# * ip link add link eth1 name eth1.601 mtu 1500 type vlan
> id 601
> *root@bahia:~# * ip link set dev eth1.601 up promisc on
> *root@bahia:~# * ip -d addr show eth1.601
> 9: eth1.601@eth1: <BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP> mtu 1500
> qdisc noqueue state UP
>     link/ether 00:50:56:a7:13:4a brd ff:ff:ff:ff:ff:ff
>     inet6 fe80::250:56ff:fea7:134a/64 scope link
>        valid_lft forever preferred_lft forever
> *root@bahia:~# ** *ip route show
> default via 200.243.1.254 dev eth0
> 200.243.1.0/24 dev eth0  proto kernel  scope link  src 200.243.1.5
> *root@bahia:~# *
>
> and.... we've the interface l2tpeth0 (L2TPv3) established with other node
> into the internet by eth0 (WAN), plugged
> with vlan601 (eth1.601) by bridge called "br-red"
>
> *root@bahia:~#* brctl show
> bridge name bridge id STP enabled interfaces
> *root@bahia:~#* brctl addbr br-red
> *root@bahia:~#* brctl addif br-red eth1.601
> *root@bahia:~#** *ip l2tp add tunnel tunnel_id 45 peer_tunnel_id 42
> udp_sport 5001 udp_dport 5000 encap udp local 200.243.1.5 remote
> 200.199.10.12
> *root@bahia:~#** *ip l2tp add session tunnel_id 45 session_id 5196755
> peer_session_id 128
> *root@bahia:~#* ip link set l2tpeth0 up promisc on master br-red
>
> *root@bahia:~#* ip link set br-red up
> *root@bahia:~#* brctl show br-red
> bridge name bridge id STP enabled interfaces
> br-red 8000.005056a7134a no eth1.601
> l2tpeth0
> *root@bahia:~# *brctl showstp br-red
> br-red
>  bridge id 8000.005056a7134a
>  designated root 8000.005056a7134a
>  root port         0 path cost   0
>  max age         20.00 bridge max age  20.00
>  hello time 2.00 bridge hello time   2.00
>  forward delay 15.00 bridge forward delay  15.00
>  ageing time 300.01
>  hello timer 1.06 tcn timer   0.00
>  topology change timer   0.00 gc timer   5.08
>  flags
>
> eth1.601 (1)
>  port id 8001 state     forwarding
>  designated root 8000.005056a7134a path cost   4
>  designated bridge 8000.005056a7134a message age timer   0.00
>  designated port 8001 forward delay timer   0.00
>  designated cost   0 hold timer   0.06
>  flags
>
> l2tpeth0 (2)
>  port id 8002 state     forwarding
>  designated root 8000.005056a7134a path cost 100
>  designated bridge 8000.005056a7134a message age timer   0.00
>  designated port 8002 forward delay timer   0.00
>  designated cost   0 hold timer   0.05
>  flags
>
> *root@bahia:~# *
> *
> *
> it's ok, my bridge "by-red" listen all traffic over my LAN (vlan 601) and
> my L2TPv3 over internet. (wan)*
> *
> *
> *
> *root@bahia:~# ** *tcpdump -nve -i *br-red* "host 10.251.0.1"
> tcpdump: WARNING: br-red: no IPv4 address assigned
> tcpdump: listening on br-red, link-type EN10MB (Ethernet), capture size
> 65535 bytes
> 20:58:17.860060 d4:ae:52:84:37:ae > ff:ff:ff:ff:ff:ff, ethertype ARP
> (0x0806), length 60: Ethernet (len 6), IPv4 (len 4), Request who-has
> 10.251.90.157 tell *10.251.0.1*, length 46
> 20:58:17.980065 d4:ae:52:84:37:ae > ff:ff:ff:ff:ff:ff, ethertype ARP
> (0x0806), length 60: Ethernet (len 6), IPv4 (len 4), Request who-has
> 10.251.153.31 tell *10.251.0.1*, length 46
> ^C
> 7 packets captured
> 7 packets received by filter
> 0 packets dropped by kernel
> *root@bahia:~# *
>
>
> +-----------------------------------------------------------------------------------------+
>  | SERVER B (BRIDGE/L2TPv3 + WIRELESS ACCESS POINT) - RECIFE |
>
> +-----------------------------------------------------------------------------------------+
>
> *root@recife:~#* ip addr show eth1 *# (WAN)*
> 3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state
> UP qlen 1000
>     link/ether a0:f3:c1:a3:c4:11 brd ff:ff:ff:ff:ff:ff
>     inet 200.199.10.12/21 brd 200.199.10.255 scope global eth1
>        valid_lft forever preferred_lft forever
>     inet6 fe80::a2f3:c1ff:fea3:c411/64 scope link
>        valid_lft forever preferred_lft forever
> *root@recife:~#* ip route show
> default via 200.199.10.254 dev eth1  proto static
> 200.199.10.0/21 dev eth1  proto kernel  scope link  src 200.199.10.12
> 192.168.1.0/24 dev br-lan  proto kernel  scope link  src 192.168.1.1
> *root@recife:~#* ip l2tp add tunnel tunnel_id 42 peer_tunnel_id 45
> udp_sport 5000 udp_dport 5001 encap udp local 200.199.10.12 remote
> 200.243.1.5
> *root@recife:~#* ip l2tp add session tunnel_id 42 session_id 128
> peer_session_id 5196755
> *root@recife:~#* ip link set dev l2tpeth0 up promisc on master br-red
> *root@recife:~#* brctl show
> bridge name     bridge id               STP enabled     interfaces
> br-lan          7fff.a0f3c1a3c40f       no              eth0
> *root@recife:~#* brctl addbr br-red
> *root@recife:~#* brctl addif br-red l2tpeth0
> *root@recife:~#* brctl addif br-red wlan0
> *root@recife:~#* ifconfig br-red up
> *root@recife:~#* ip link set br-red up
> *root@recife:~#* brctl show
> bridge name     bridge id                     STP enabled     interfaces
> br-lan                7fff.a0f3c1a3c40f       no                     eth0
> br-red                8000.1ae0f4a30221  no                     l2tpeth0
>
>            wlan0
> *root@recife:~#*
> *
> *
> *....::: RESUME :::...*
>
> 1) sorry for the long email....
> 2) when i'm "recife hostspot"... I can join in wireless "Recife Wireless"
> from my device, but i can't receive ip from dhcp (10.60.61.1).
> 3) from "server A[bahia] (bridge with vlan601 network) and "server B
> [recife]", i can "see/listen" the broadcast request from my
> device mac "5c:95:ae:22:d6:6e" like below.
>
> *root@bahia:~# *tcpdump -nve -i br-red "ether host ether
> 5c:95:ae:22:d6:6e"
> 00:08:52.653667 5c:95:ae:22:d6:6e > ff:ff:ff:ff:ff:ff, ethertype IPv4
> (0x0800), length 342: (tos 0x0, ttl 255, id 37839, offset 0, flags [none],
> proto UDP (17), length 328)
>     0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from
> 5c:95:ae:22:d6:6e, length 300, xid 0xe6f1d0a5, Flags [none]
>           Client-Ethernet-Address 5c:95:ae:22:d6:6e
>           Vendor-rfc1048 Extensions
>             Magic Cookie 0x63825363
>             DHCP-Message Option 53, length 1: Discover
>             Parameter-Request Option 55, length 6:
>               Subnet-Mask, Default-Gateway, Domain-Name-Server, Domain-Name
>               Option 119, Option 252
>             MSZ Option 57, length 2: 1500
>             Client-ID Option 61, length 7: ether 5c:95:ae:22:d6:6e
>             Lease-Time Option 51, length 4: 7776000
>             Hostname Option 12, length 14: "Straces-iPhone"
> ^C
> 1 packets captured
> 1 packets received by filter
> *root@bahia:~#*
>
> same thing result at "bridge a" (*root@recife:~#) *side...
>
> 4) the strangest thing of all and that, from bridge-b (recife). i can get
> ip from dhcp/broadcast request over L2TPv3...
> but without option "broadcast" i can't receive ip from dhcp (10.61.60.1)
>
> *root@recife:~#* udhcpc -B -i br-red
> udhcpc (v1.19.4) started
> Sending discover...
> Sending select for 10.251.157.22...
> Lease of 10.251.157.22 obtained, lease time 300
> udhcpc: ifconfig br-red 10.251.157.22 netmask 255.255.0.0 broadcast +
> udhcpc: setting default routers: 10.251.0.1
> *root@recife:~# *ip route add 200.243.1.5 via 200.199.10.254 dev eth1
> *root@recife:~# *ip route show
> default via 10.251.0.1 dev br-red
> 10.251.0.0/16 dev br-red  proto kernel  scope link  src 10.251.157.22
> 200.199.10.0/21 dev eth1  proto kernel  scope link  src 200.199.10.12
> 200.243.1.5 via 200.199.10.254 dev eth1
> 192.168.1.0/24 dev br-lan  proto kernel  scope link  src 192.168.1.1
> *root@recife:~#* ping -c2 10.251.0.1
> PING 10.251.0.1 (10.251.0.1): 56 data bytes
>
> --- 10.251.0.1 ping statistics ---
> 2 packets transmitted, 0 packets received, 100% packet loss
> *root@recife:~#*
>
> 5) output of tcpdump listen the bridge "br-red" request from
> bridge-a-natal http://pastebin.com/t8wn3zRK
> 6) output of tcpdump listen the bridge "br-red" request from
> bridge-b-recife http://pastebin.com/njTQfd5k
> 7) after several researches i found the kernel options to set like
> "arp_filter", "bridge-nf-*",... but i don't have
> idea which option should enable / disable. tried some combinations but
> without success....
> 8) the DHCP-OFFER doesn't forward by "bridge-a"...  problems with unicast?
> multicast? arp_proxy? ....
> 9) we need join in the network by wireless and access the server
> 10.251.0.1 over bridge/l2tpv3 (unmanaged)
> 10) in our case, can use only L2TPv3. (may not be OpenVPN, ...)
> 11) all is Linux, without any iptables rules.
> 12) who will win a beer?! =]
>
> Best regards,
> Jorge Pereira
>