[HamWAN PSDR] CapitolPark <-> QueenAnne link
Bart Kus
me at bartk.us
Fri Mar 30 15:30:22 PDT 2018
Moving PSDR@ to BCC so as to not continue spamming people as we debug this.
Ugh, the problem is not presenting itself today in the same way. :( But
here was the gist of it as of last night:
21:17 <@EO_> [eo at QueenAnne.Haystack] /routing ospf lsa> /ip route check
44.24.242.36
21:17 <@EO_> status: ok
21:17 <@EO_> interface: wlan1
21:17 <@EO_> nexthop: 44.24.242.39
21:17 <@EO_> [eo at QueenAnne.Haystack] /routing ospf lsa> /ip route check
44.24.242.37
21:17 <@EO_> status: ok
21:17 <@EO_> interface: ether1
21:17 <@EO_> nexthop: 44.24.241.37
1) The modem being asked about the route decision is
"QueenAnne.Haystack", which is @ Haystack, RF-linked to QueenAnne site
and running OSPF with it.
2) The destination IP of 44.24.242.36 is bound to QueenAnne.CapitolPark,
which is @ CapitolPark, RF-linked to QueenAnne site and running OSPF
with it.
3) The destination IP of 44.24.242.37 is bound to CapitolPark.QueenAnne,
which is @ QueenAnne, RF-linked to CapitolPark site and running OSPF
with it.
In other words, .36 and .37 are 2 sides of an RF link between QueenAnne
and CapitolPark. .36 sits on the CapitolPark side and .37 sits on the
QueenAnne side. The shortest path to both IPs ought to be via the
Haystack->QueenAnne wlan1 RF hop, and then through the LAN @ QueenAnne
for .37, and through a 2nd RF hop for .36. That means .36 ought to be
MORE DISTANT than .37. Meanwhile, the routing table lookup shows wlan1
being taken for .36 (the further destination) and ether1 being taken for
.37 (the closer destination). The ether1 path is longer than the RF
path, as it has to traverse the Haystack LAN, then an RF link to K7NVH,
then a VPN tunnel to Seattle, then another RF link to QueenAnne, then
the QueenAnne LAN. This weird routing seems to have gone away today.
The strange thing is, the route costs in OSPF persist at being weird:
65 44.24.242.36/32 intra-area 30
44.24.242.39 wlan1
66 44.24.242.37/32 intra-area 40
44.24.242.39 wlan1
Why would .37 be more costly here than .36? Here are the traces today:
[eo at QueenAnne.Haystack] /routing ospf route> /tool traceroute 44.24.242.36
# ADDRESS LOSS SENT LAST AVG BEST
WORST STD-DEV STATUS
1 44.24.242.39 0% 2 31.7ms 33.7 31.7
35.7 2
2 44.24.241.83 0% 2 4.8ms 11.2 4.8
17.5 6.4
3 44.24.242.36 0% 2 11.5ms 9.7 7.8
11.5 1.9
[eo at QueenAnne.Haystack] /routing ospf route> /tool traceroute 44.24.242.37
# ADDRESS LOSS SENT LAST AVG BEST
WORST STD-DEV STATUS
1 44.24.242.39 0% 2 22.6ms 13.5 4.3
22.6 9.2
2 44.24.242.37 0% 2 4.1ms 4 3.9
4.1 0.1
All interface costs along the path are "10", so I don't get this OSPF
calculation, even though the resulting route decision is finally correct
today. Here are the LSAs from CapitolPark.QueenAnne and
QueenAnne.CapitolPark, respectively, as seen by QueenAnne.Haystack:
[eo at QueenAnne.Haystack] > /routing ospf lsa print detail where
originator=44.24.241.83
instance=default area=backbone type=router id=44.24.241.83
originator=44.24.241.83 sequence-number=0x80000DB4 age=1225
checksum=0x6BD0 options="E" body=
flags=
link-type=Point-To-Point id=44.24.240.7 data=*44.24.242.37*
metric=10
link-type=Stub id=*44.24.242.36* data=255.255.255.255 metric=10
link-type=Transit id=44.24.241.84 data=44.24.241.83 metric=10
[eo at QueenAnne.Haystack] > /routing ospf lsa print detail where
originator=44.24.240.7
instance=default area=backbone type=router id=44.24.240.7
originator=44.24.240.7 sequence-number=0x800045DD age=1240
checksum=0x754E options="E" body=
flags=
link-type=Point-To-Point id=44.24.241.83 data=*44.24.242.36*
metric=10
link-type=Stub id=*44.24.242.37* data=255.255.255.255 metric=10
link-type=Transit id=44.24.240.7 data=44.24.240.7 metric=10
instance=default area=backbone type=network id=44.24.240.7
originator=44.24.240.7 sequence-number=0x800000C4 age=952
checksum=0xD1F1 options="E" body=
netmask=255.255.255.240
routerId=44.24.240.7
routerId=44.24.240.3
routerId=44.24.240.1
routerId=44.24.240.4
routerId=44.24.240.5
routerId=44.24.240.6
I have boldified the relevant IPs in each LSA. Can you make heads or
tails of why the weird costs are being computed?
--Bart
On 3/30/2018 9:59 AM, Dylan Ambauen wrote:
> Wow, Bart.
>
> Let me look back at my ospf ptp configs. I'm no expert, but I recall
> it was a process of elimination to find the right settings. Are the
> ptp neighbors linking ospf in just one direction?
>
>
>
>
> On Thu, Mar 29, 2018, 23:17 Bart Kus <me at bartk.us
> <mailto:me at bartk.us>> wrote:
>
> After hours of debugging, I got this 20MHz single-polarity link
> moving up to 55Mbit. A high resolution spectrum analysis on both
> sides did indeed show a better frequency to use for the link.
> Spectrum analysis captures here:
>
> https://imgur.com/a/4H7GB
>
> There was also an IP conflict between two modems @ Capitol Park.
> The conflicting IP has been removed from CapitolPark-S3.
>
> The QueenAnne modem used for the link is not one used anywhere
> else on the network. It's a very low-end modem, and as a result
> it was having CPU/RAM starvation issues when running our regular
> diagnostic tools, which lead to out-of-memory conditions and
> kernel crashes. A different test methodology had to be used to
> verify the link speed (testing through the modem, instead of to
> the modem).
>
> The modem that links QueenAnne with the Westin building (on the
> QueenAnne side) had a mis-configured OSPF router-id. This was fixed.
>
> I'm still seeing weird routing decisions being made by OSPF.
> These are triggered by our point-to-point route entries
> (44.24.242.0/24 <http://44.24.242.0/24> space). More research
> needs to be done here, and perhaps a re-write of how we define
> point-to-point interface addresses. Any OSPF experts in the house?
>
> I also discovered R1.QueenAnne was still vulnerable to hacking due
> to a mis-configuration of its control software. It missed the
> updates that were sent out to the whole network. This has been
> fixed now. R1.QueenAnne also didn't have the diagnostic
> bandwidth-server setup correctly. This was fixed.
>
> With the CapitolPark-QueenAnne link performing well now:
>
> [eo at CapitolPark-QueenAnne] /system resource> /tool bandwidth-test
> 44.24.241.81 direction=both
> status: running
> duration: 57s
> tx-current: 28.0Mbps
> tx-10-second-average: 28.4Mbps
> tx-total-average: 27.5Mbps
> rx-current: 27.6Mbps
> rx-10-second-average: 28.0Mbps
> rx-total-average: 27.0Mbps
> lost-packets: 288
> random-data: no
> direction: both
> tx-size: 1500
> rx-size: 1500
>
> its OSPF config has been reset to a normal preference level, so
> that packets no longer try to avoid that link as they are routed
> through the network. This link can be sped up by upgrading to a
> dual-polarity modem @ CapitolPark.
>
> While testing if the OSPF hop cost was being calculated correctly
> in the Beacon-Haystack-QueenAnne RF link (they both connect to the
> same dish @ Haystack), I discovered a mis-config on the
> Haystack.Beacon modem (bad LAN IP binding) which was preventing it
> from bringing up OSPF on its LAN interface. This was fixed and
> that modem should act like an actual router now, moving traffic.
>
> During the same Beacon testing, I was reminded that our
> Baldi-Beacon RF link sucks
> <https://monitoring.hamwan.net/cacti/graph.php?action=view&local_graph_id=919&rra_id=all>.
> It was optimized for speed to Tukwila, which is now gone, so a
> trip needs to be scheduled to Baldi to rotate the dish a few
> degrees north and get that link going strong.
>
> I normally wouldn't send this kind of verbose email to psdr@, but
> I hope it's illuminating as to the type and extent of work
> required to keep this network running well.
>
> --Bart
>
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