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Wednesday, 27. February 2013 | Week 08 |
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.: Howto generate DH parameters for OpenVPN
openssl gendh -out dh4096.pem 4096
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18:29 | Linux | Permalink |
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Monday, 25. February 2013 | Week 08 |
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.: Orange Routing 2
I did another test of the Orange Routing. Running a traceroute to my server in Zurich and one to my vhost in Frankfurt. First another version of the already familier traceroute to my server in Zurich:
HOST: Andreass-MacBook-Pro.local Loss% Snt Last Avg Best Wrst StDev
1.|-- 172.20.10.1 0.0% 5 8.0 3.7 2.1 8.0 2.5
2.|-- 10.8.8.67 0.0% 5 174.8 114.9 56.7 205.6 69.8
3.|-- 10.8.12.10 0.0% 5 126.8 108.4 67.7 171.3 42.8
4.|-- 192.168.249.201 0.0% 5 73.4 82.7 61.9 111.5 20.5
5.|-- 192.168.253.191 0.0% 5 54.0 64.9 54.0 75.9 9.3
6.|-- 192.168.250.203 0.0% 5 64.7 69.2 57.3 79.2 8.4
7.|-- 10.10.10.10 0.0% 5 56.8 65.5 56.8 72.1 7.7
8.|-- 10.255.200.1 0.0% 5 65.9 87.3 60.1 146.6 35.1
9.|-- pos0-1-1-1.gencr1.geneve. 0.0% 5 84.8 117.1 76.4 162.5 36.9
10.|-- pos14-0-1.pascr4.paris.op 0.0% 5 88.1 118.0 88.1 168.3 36.7
11.|-- ge6-0-0.br2.par2.alter.ne 0.0% 5 76.5 90.5 76.5 109.1 12.0
12.|-- so-2-3-0.xt2.zur3.alter.n 0.0% 5 76.8 109.1 76.8 203.2 53.1
13.|-- pos2-0.gw4.zur4.alter.net 0.0% 5 88.8 98.7 84.3 143.4 25.2
14.|-- uch200193-gw.customer.alt 0.0% 5 90.7 85.3 74.1 93.5 8.0
15.|-- whale29.open.ch 0.0% 5 88.9 97.7 88.9 104.7 6.3
16.|-- orca8.open.ch 0.0% 5 90.8 94.8 90.8 102.8 4.9
17.|-- real.jaggi.info 20.0% 5 234.8 130.0 92.8 234.8 69.9
Now the traceroute to the vhost in Frankfurt:
HOST: Andreass-MacBook-Pro.local Loss% Snt Last Avg Best Wrst StDev
1.|-- 172.20.10.1 0.0% 5 15.2 13.1 1.9 44.5 18.4
2.|-- 10.8.8.115 0.0% 5 72.6 74.0 67.2 81.3 6.8
3.|-- 10.8.12.10 0.0% 5 80.7 75.0 64.0 89.6 10.3
4.|-- 192.168.249.201 0.0% 5 65.1 78.9 65.1 94.0 12.3
5.|-- 192.168.253.191 0.0% 5 73.1 70.4 66.5 73.3 2.8
6.|-- 192.168.250.203 0.0% 5 69.5 73.9 66.3 86.6 7.7
7.|-- 10.10.10.10 0.0% 5 67.0 72.7 67.0 80.0 4.9
8.|-- 10.255.200.1 0.0% 5 70.9 74.4 69.7 86.4 7.0
9.|-- pos0-1-1-1.gencr1.geneve. 0.0% 5 77.2 83.4 75.9 99.4 9.4
10.|-- pos3-1-0.zurcr1.zurich.op 0.0% 5 83.8 103.2 83.8 146.9 26.3
11.|-- pos0-9-4-0.ffttr1.frankfu 0.0% 5 102.9 103.6 98.7 108.8 4.9
12.|-- leaseweb-9.gw.opentransit 0.0% 5 87.6 88.8 85.3 93.2 3.0
13.|-- te3-1.core-2.fra.leaseweb 0.0% 5 85.4 91.5 85.4 106.1 8.5
14.|-- hosted-by.leaseweb.com 0.0% 5 90.2 94.1 84.7 112.5 11.0
15.|-- ??? 100.0 5 0.0 0.0 0.0 0.0 0.0
16.|-- 0.jaggi.info 20.0% 5 89.9 117.5 86.3 205.5 58.7
As you can see, the RTT is higher for the server in Zurich than for the vhost in Frankfurt! (keep in mind that source of these measurement is my laptop in the train 8 minutes away from Zurich now)
So Orange has higher latency to hosts in the same region/city than to hosts in another country which are more than 350km away. :-( The next time I choose a mobile provider it might be good to analyse its BGP peerings and routing policies first...
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13:20 | Networking | Permalink |
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.: Orange Routing
While in the train from Bern to Zurich, I did a traceroute towards the server which currently hosts this weblog (it is located at Open Systems in Zurich). The connection starts on my laptop and is thethered via my cell to the Orange backbone.
HOST: Andreass-MacBook-Pro.local Loss% Snt Last Avg Best Wrst StDev
1.|-- 172.20.10.1 0.0% 5 2.0 12.1 1.7 33.2 14.6
2.|-- 10.8.8.67 0.0% 5 52.2 373.4 52.2 1241. 504.8
3.|-- 10.8.12.10 0.0% 5 50.9 347.4 50.9 1143. 453.3
4.|-- 192.168.249.201 0.0% 5 51.2 282.7 51.2 1042. 426.8
5.|-- 192.168.253.191 0.0% 5 51.2 226.2 44.5 942.2 400.3
6.|-- 192.168.250.203 0.0% 5 51.4 206.7 37.9 847.5 358.2
7.|-- 10.10.10.10 0.0% 5 50.0 181.4 29.6 746.9 316.2
8.|-- 10.255.200.1 0.0% 5 50.0 172.2 36.9 645.6 264.9
9.|-- 193.251.248.145 0.0% 4 60.2 59.8 46.2 81.9 15.8
10.|-- 193.251.240.53 0.0% 4 70.0 76.4 64.9 101.6 16.9
11.|-- 146.188.112.77 0.0% 4 70.4 74.0 69.2 83.8 6.7
12.|-- 146.188.5.1 0.0% 4 70.6 71.7 58.1 88.1 12.3
13.|-- 146.188.4.194 0.0% 4 70.5 61.9 51.6 70.9 10.2
14.|-- 146.188.64.74 0.0% 4 71.3 69.2 58.8 75.4 7.2
15.|-- 213.156.230.29 0.0% 4 71.5 78.3 62.6 108.9 20.7
16.|-- 213.156.229.8 0.0% 4 72.2 75.2 70.4 81.9 5.1
17.|-- 213.156.229.222 25.0% 4 80.8 76.2 61.2 86.5 13.3
You can see that the traffic is passed through 8 different routers inside the Orange backbone (using IPs from all three RFC1918 ranges...) before it is let onto the Internet.
And then the real fun starts (let's use DNS names for this):
HOST: Andreass-MacBook-Pro.local Loss% Snt Last Avg Best Wrst StDev
1.|-- 172.20.10.1 0.0% 5 2.0 12.2 1.9 33.3 14.5
2.|-- 10.8.8.67 0.0% 5 44.2 345.6 27.0 1167. 494.2
3.|-- 10.8.12.10 0.0% 5 52.2 308.9 27.0 1104. 462.4
4.|-- 192.168.249.201 0.0% 5 33.4 264.9 27.2 1014. 427.1
5.|-- 192.168.253.191 0.0% 5 30.3 227.5 27.3 952.9 406.4
6.|-- 192.168.250.203 0.0% 5 50.4 200.7 27.0 860.0 368.7
7.|-- 10.10.10.10 0.0% 5 72.4 193.5 30.5 779.2 327.8
8.|-- 10.255.200.1 0.0% 5 31.8 166.8 27.6 688.0 291.5
9.|-- pos0-1-1-1.gencr1.geneve. 0.0% 4 50.8 55.0 47.6 67.1 8.6
10.|-- pos14-0-1.pascr4.paris.op 0.0% 4 61.0 64.4 57.7 78.5 9.5
11.|-- ge6-0-0.br2.par2.alter.ne 0.0% 4 70.8 56.3 48.4 70.8 9.9
12.|-- so-2-3-0.xt2.zur3.alter.n 0.0% 4 108.9 65.6 48.0 108.9 29.2
13.|-- pos2-0.gw4.zur4.alter.net 0.0% 4 51.7 55.5 50.3 68.8 8.8
14.|-- uch200193-gw.customer.alt 0.0% 4 171.8 83.6 50.7 171.8 58.8
15.|-- whale29.open.ch 0.0% 4 132.1 90.0 59.2 132.1 32.7
16.|-- orca8.open.ch 0.0% 4 72.4 66.8 58.6 73.5 7.3
17.|-- real.jaggi.info 25.0% 4 80.2 64.7 56.2 80.2 13.4
As we see, Orange injects their mobile data traffic into the Internet in Geneva (pos0-1-1-1.gencr1.geneve.).
Then it is first sent to Paris (pas14-0-1.pascr4.paris.op and ge6-0-0.br2.par2.alter.ne) and from there back to Zurich (so-2-3-0.xt2.yur3.alter.n and all the following hosts).
I can kind of understand that the traffic is routed via Geneva (main Orange infrastructure is there), but why is it sent to Paris? (especially since Geneva<->Zurich is the main Internet connection inside Switzerland where most of the countries fiber is buried).
I guess this explains why my mobile data speed is not always as fast as I like it to be...
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12:34 | Networking | Permalink |
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Monday, 18. February 2013 | Week 07 |
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.: Administrative Distance
When using more than one dynamic routing protocol, make sure to know their administrative distance.
Further it is usually a bad idea to redistribute routes from a dynamic routing protocol into another one with a lower administrative distance. Especially when having multiple handover points between the two protocols.
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08:39 | Networking | Permalink |
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Sunday, 17. February 2013 | Week 06 |
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.: I ♡ snow

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17:31 | Misc | Permalink |
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Thursday, 14. February 2013 | Week 06 |
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.: Computer Science
 via boingboing.net
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18:07 | Misc | Permalink |
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Wednesday, 13. February 2013 | Week 06 |
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.: Updated HAVP blacklist script
The HAVP blacklist script chocked on some entries from PhishTank. These issues have been fixed with some more sed magic and I've put and updated version of the script on Github.
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18:02 | Linux | Permalink |
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.: Verify a BGP MD5 password before session turnup
When setting up a new BGP peering, you may want to test if your peering partner uses the correct MD5 password without bringing up your side of the session.
For this the tcpdump option -M can be used to supply the MD5 password when sniffing the traffic of the new peer:
tcpdump -ni eth0 -M MyBgPMd5PaSsWoRd tcp port 179
tcpdump will then verify the MD5 signature for every packet where it finds a MD5 signature TCP option as specified in RFC2385.
In the output you will see md5valid for packets where your password matches the MD5 signature or md5invalid for packets where your password does not match the MD5 signature. If you see neither md5valid nor md5invalid then the peer did not configure any MD5 BGP password.
If you want to check for mismatching MD5 passwords after you bring up the BGP session, just look into the kernel log. Linux reports invalid MD5 TCP signatures like this:
MD5 Hash failed for (1.2.3.4, 56789)->(1.2.3.5, 179)
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09:02 | Networking | Permalink |
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Tuesday, 5. February 2013 | Week 05 |
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.: Configure unattached Bridge Interfaces in Debian
When working with virtualization technologies like KVM on Debian, you might need to configure bridge interfaces which are not attached to a physical interfaces (for example for a non-routed management network or similar).
Debian uses the directive bridge_ports in /etc/network/interfaces to indicate whether an interface is a bridge interface or not.
The syntax checker does not accept an empty bridge_ports directive since he expects a list of physical interfaces to attach to the bridge interface.
When needing a bridge interface without any physical interfaces attached, usually people configure this interface by hand or with a special script.
Since I manage /etc/network/interfaces with my Puppet module, I would like to use it to configure all network interfaces including the unattached bridge interfaces.
It turns out that this can be done by passing none as parameter for the bridge_ports directive like this:
interface br0 inet static
address 192.0.2.1
netmask 255.255.255.0
bridge_ports none
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08:42 | Linux | Permalink |
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