28 Apr

Tanzania Telecom leaking Telia routes to Tata

Last night I was looking at routing tables and saw a interesting case where for a specific route.

 

Here’s what I got from Tata’s AS6453 looking glass:

Router: gin-ldn-core4
Site: UK, London, LDN
Command: show ip bgp 117.219.227.229

BGP routing table entry for 117.219.224.0/20
Bestpath Modifiers: deterministic-med
Paths: (4 available, best #4)
Multipath: eBGP
17 18 19

33765 1299 3549 9829, (received-only)
ix-3-1-2.core4.LDN-London. from ix-3-1-2.core4.LDN-London. (ix-3-1-2.core4.LDN-London.)
Origin IGP, valid, external

4755 9829
mlv-tcore2. (metric 3605) from l78-tcore2. (66.110.10.234)
Origin IGP, valid, internal
Community:
Originator: 66.110.10.215

4755 9829
mlv-tcore2. (metric 3605) from l78-tcore1. (66.110.10.237)
Origin IGP, valid, internal
Community:
Originator: 66.110.10.215

4755 9829
mlv-tcore2. (metric 3605) from ldn-mcore3. (ldn-mcore3.)
Origin IGP, valid, internal, best
Community:
Originator: 66.110.10.215

 

The first route in table seems pretty weird. AS path is 33765 1299 3549 9829 i.e clearly AS33765 sitting in middle of AS6453 and AS1299. This must be a route leak since Tata AS6453 and Telia AS1299 are way too bigger then Tanzania telecom and hence there’s no possibility of Tata transitting via Tanzania telecom. Though issue seems for just one specific route for BSNL which Tanzania telecom is learning from Telia, which further is getting from Global Crossing AS3549 (one of upstreams of BSNL). 

As per RADB both Telia and Tata Comm are upstreams of AS33765.

anurag:~ anurag$ whois -h whois.radb.net as1299 | grep 33765
import: from AS33765 action pref=50; accept AS-33765
export: to AS33765 announce ANY
mp-import: afi ipv6 from AS33765 accept AS-33765
mp-export: afi ipv6 to AS33765 announce ANY
anurag:~ anurag$
anurag:~ anurag$
anurag:~ anurag$ whois -h whois.radb.net as6453 | grep 33765
import: from AS33765 action pref = 50; accept AS33765
export: to AS33765 announce ANY
anurag:~ anurag$

 

With hope that you are not leaking routes between two tier 1 networks, time for me to start my day! 🙂

26 Apr

IRINN | APNIC inetnum range confusion

Last week I saw an interesting post at APNIC mailing list about IRINN (recently formed NIR in Indian region). 

 

Poster Jimmy was concerned about IRINN’s netname

inetnum: 0.0.0.0 – 255.255.255.255
netname: IRINN-BROADCAST-ADDRESSES
descr: Broadcast addresses
descr: These addresses cannot (should not) be routed on the Internet.
country: IN
admin-c: IH1-IN
tech-c: IH1-IN
status: ALLOCATED PORTABLE
remarks: send spam and abuse report to info@irinn.in
mnt-by: IRINN-HM
mnt-irt: IRT-IRINNHM-IN
mnt-lower: IRINN-HM
changed: hostmaster2@irinn.in 20130420
source: IRINN

 

As per first two lines entire IPv4 address space i.e 0.0.0.0/0 (ranging from 0.0.0.0 to 255.255.255.255) was put as IRINN-Broadcast while expected was IANA broadcast (since IANA sits on top in this RIR & NIR hierarchy).

Right after that post IRINN came into action and changed values to:

inetnum: 255.0.0.0 – 255.255.255.255
netname: IANA-BROADCAST-ADDRESSES
descr: Broadcast addresses
descr: These addresses cannot (should not) be routed on the Internet.
descr: http://www.apnic.net/db/RIRs.html
country: US
admin-c: HM20-AP
tech-c: NO4-AP
remarks: This is a placeholder object to ensure no objects are created
remarks: in the enclosing range.
mnt-by: MAINT-APNIC-AP
mnt-lower: MAINT-APNIC-AP
changed: apnic-dbm@apnic.net 19991214
changed: hm-changed@apnic.net 20040926
status: ALLOCATED PORTABLE
source: APNIC

 

This had correct netname suggesting IANA but source is APNIC and moreover it got a really interesting inetnum i.e 255.0.0.0 to 255.255.255.255. This really sounded bit weird to me as I was expecting entire IPv4 address range here and start from 255.0.0.0 rather then from 0.0.0.0 sounds confusing. 

 

I did some testing and saw results from whois db were different based on query. I was getting range from 255.0.0.0 to 255.255.255.255 if I query APNIC db for 0.0.0.0/0 while for 0.0.0.0 (without /0) I was getting expected range 0.0.0.0 to 255.255.255.255. I posted about this in APNIC mailing list to figure out reason for these strange numbers.

I got a really interesting reply from Leo Vegoda from ICANN:

I agree that it seems quite odd. 255/8 is part of 240/4. In 240/4 the only address whose use has been defined is 255.255.255.255, which is used for limited broadcast. The rest of 255/8 does not (yet) have a defined use. You can find the details here: http://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xml

Regards, Leo

Right after his reply, Guangliang from APNIC posted clarification and actually fix too. 🙂

Thanks to Anurag for pointing out this and Leo for your clarifications. The inetnum object 255.0.0.0 – 255.255.255.255 was created in 1999 to reflect that Broadcast reservation. We have now removed it from the APNIC whois database to avoid any confusion.

Best regards,

Guangliang

 

So yet another interesting case from internet world. Time for me to get back to work, have a good time ahead! 🙂

11 Apr

Creating a cable for fast USB charging

When I was in US last time, I picked a nice charger with it’s own backup from Amazon. It’s PowerGen charger with a storage capacity of 8400mAh with two USB ports for output (one with 2Amps output and other with 600mA with 5V standard USB).

IMG_20130411_015748

This is a amazing product since 8400mAh is really huge amount power. My phone’s battery has a capacity of 1750mAh and theoretically speaking this can charge battery from 0 to full around 4 times. In practical experience I have tried for around 3 times during long flights. Never really needed to go beyond that point.
The charging cable which came with this charger has something special – It’s a “charging only” cable without any data connection capability. The charging only cable carries only “electrical connectivity” via + and – wires without any data pins (D+ and D- shorted). The advantage is that charging speed with this cable was really fast and I really enjoyed using it with external charger as well as my iPad’s charger which has a 2A output (which brings 2A x 5V = 10W power).
In theory these charging only cables give very fast charging because they don’t put USB data connection. A standard USB port on computer has power limits and device is signaled to pull more power via “shorted data pins”. Usually device is connected to 600mA or even less in data+charging mode, while such shorting brings power to max of port which is usually 1A for most of ports (and 2Amps for iPad charger).
Unfortunately connector of cable which came with my powergen charger went pretty loose.
Tonight I decided to make an extra data cable which was lying around into “charging only” cable by shorting it’s D+ and D- mins. It was pretty easy except that actual wires are really thin and I had slightly hard time in removing insulation without breaking them off.
 
 

Steps for creating a “charging only” cable

 
Step 1 – Pick a standard USB data cable

Cable before starting:

IMG_20130411_0055151

Step 2 – Cut it right from middle and peal off outer insulation

It will have 4 wires – Red & black (for electrical current flow), white & green (for data connection)

IMG_20130411_005712

Step 3 – Now idea is to short the data pins (green and white) going towards phone while just leave white and green going towards USB port/charger side disconnected. Red and black should be connected as normal for electrical connectivity.

IMG_20130411_011227

Step 4– That’s pretty much it. Just insulate final red and black connection in a way to make sure they never short.

This is how cable looks like in my case after shorting data pins and insulting it back.

IMG_20130411_011539

That’s about it.

Back to work for now! 🙂