Well-known multicast addresses

A lot of dynamic routing protocols uses ip multicast for neighbor discovery, hellos and other things.
Here are some well known multicast adresses:

224.0.0.1 all hosts on a subnet
224.0.0.2 all routers on a subnet
224.0.0.4 Distance Vector Multicast Routing Protocols (DVMRP)
224.0.0.5 OSPF routers
224.0.0.6 OSPF designated routers
224.0.0.9 RIP Version 2 routers
224.0.0.10 EIGRP routers
224.0.0.13 Protocol independent Multicast (PIM) routers

Solaris Network Configuration

Solaris Network configuration is a little bit different to Debian.
Because i always forget it, there’s a quick explanation of the necessary steps (taken from here and used with Solaris 5,6,7,8 +9).
/etc-Files
All configuration data, such as IP addresses, gateways, and so on, can be defined and changed at runtime level.
But first of all you have to [...]

Create Wireshark-readable file with tcpdump

Sometimes, it’s necessary to capture packets with tcpdump on a machine without running X-Windows installation.
But most people are not such  cracks, that they can read the confusing output on the console (me included).
To get a better overview, i prefer Wireshark (former known as Ethereal).
With the following tcpdump-flags, you can create a file in .pcap format [...]

Convert dBm to milliwatts (mW)

Sometimes you have to convert a dBm value to milliwatts, e.g. when you retrieve the output power of a laser or a xDSL port…
You can calculate these values with the following formulas or have a look in the attached conversion table.
mW to dBm:              dBm=10*log10(P/1mW)
dBm to mW:              mW=10(dBm/10)
dBm to mW conversion table

dBm
mW
dBm
mW
dBm
mW
dBm
mW
dBm
mW

0.0
1.00000
0.1
1.02329
0.2
1.04713
0.3
1.07152
0.4
1.09648

0.5
1.12202
0.6
1.14815
0.7
1.17490
0.8
1.20226
0.9
1.23027

1.0
1.2589
1.1
1.2882
1.2
1.3183
1.3
1.3490
1.4
1.3804

1.5
1.4125
1.6
1.4454
1.7
1.4791
1.8
1.5136
1.9
1.5488

2.0
1.5849
2.1
1.6218
2.2
1.6596
2.3
1.6982
2.4
1.7378

2.5
1.7783
2.6
1.8197
2.7
1.8621
2.8
1.9055
2.9
1.9498

3.0
1.9953
3.1
2.0417
3.2
2.0893
3.3
2.1380
3.4
2.1878

3.5
2.2387
3.6
2.2909
3.7
2.3442
3.8
2.3988
3.9
2.4547

4.0
2.5119
4.1
2.5704
4.2
2.6303
4.3
2.6915
4.4
2.7542

4.5
2.8184
4.6
2.8840
4.7
2.9512
4.8
3.0200
4.9
3.0903

5.0
3.1623
5.1
3.2359
5.2
3.3113
5.3
3.3884
5.4
3.4674

5.5
3.5481
5.6
3.6308
5.7
3.7154
5.8
3.8019
5.9
3.8905

6.0
3.9811
6.1
4.0738
6.2
4.1687
6.3
4.2658
6.4
4.3652

6.5
4.4668
6.6
4.5709
6.7
4.6774
6.8
4.7863
6.9
4.8978

7.0
5.0119
7.1
5.1286
7.2
5.2481
7.3
5.3703
7.4
5.4954

7.5
5.6234
7.6
5.7544
7.7
5.8884
7.8
6.0256
7.9
6.1660

8.0
6.3096
8.1
6.4565
8.2
6.6069
8.3
6.7608
8.4
6.9183

8.5
7.0795
8.6
7.2444
8.7
7.4131
8.8
7.5858
8.9
7.7625

9.0
7.9433
9.1
8.1283
9.2
8.3176
9.3
8.5114
9.4
8.7096

9.5
8.9125
9.6
9.1201
9.7
9.3325
9.8
9.5499
9.9
9.7724

10.0
10.0000
10.1
10.2329
10.2
10.4713
10.3
10.7152
10.4
10.9648

10.5
11.2202
10.6
11.4815
10.7
11.7490
10.8
12.0226
10.9
12.3027

11.0
12.5893
11.1
12.8825
11.2
13.1826
11.3
13.4896
11.4
13.8038

11.5
14.1254
11.6
14.4544
11.7
14.7911
11.8
15.1356
11.9
15.4882

12.0
15.8489
12.1
16.2181
12.2
16.5959
12.3
16.9824
12.4
17.3780

12.5
17.7828
12.6
18.1970
12.7
18.6209
12.8
19.0546
12.9
19.4984

13.0
19.9526
13.1
20.4174
13.2
20.8930
13.3
21.3796
13.4
21.8776

13.5
22.3872
13.6
22.9087
13.7
23.4423
13.8
23.9883
13.9
24.5471

14.0
25.1189
14.1
25.7040
14.2
26.3027
14.3
26.9153
14.4
27.5423

14.5
28.1838
14.6
28.8403
14.7
29.5121
14.8
30.1995
14.9
30.9030

15.0
31.6228
15.1
32.3594
15.2
33.1131
15.3
33.8844
15.4
34.6737

15.5
35.4813
15.6
36.3078
15.7
37.1535
15.8
38.0189
15.9
38.9045

16.0
39.8107
16.1
40.7380
16.2
41.6869
16.3
42.6580
16.4
43.6516

16.5
44.6684
16.6
45.7088
16.7
46.7735
16.8
47.8630
16.9
48.9779

17.0
50.1187
17.1
51.2861
17.2
52.4807
17.3
53.7032
17.4
54.9541

17.5
56.2341
17.6
57.5440
17.7
58.8844
17.8
60.2560
17.9
61.6595

18.0
63.0957
18.1
64.5654
18.2
66.0693
18.3
67.6083
18.4
69.1831

18.5
70.7946
18.6
72.4436
18.7
74.1310
18.8
75.8578
18.9
77.6247

19.0
79.4328
19.1
81.2831
19.2
83.1764
19.3
85.1138
19.4
87.0964

19.5
89.1251
19.6
91.2011
19.7
93.3254
19.8
95.4993
19.9
97.7237

20.0
100.0000
20.1
102.3293
20.2
104.7129
20.3
107.1519
20.4
109.6478

20.5
112.2018
20.6
114.8154
20.7
117.4898
20.8
120.2264
20.9
123.0269

21.0
125.8925
21.1
128.8250
21.2
131.8257
21.3
134.8963
21.4
138.0384

21.5
141.2538
21.6
144.5440
21.7
147.9108
21.8
151.3561
21.9
154.8817

22.0
158.4893
22.1
162.1810
22.2
165.9587
22.3
169.8244
22.4
173.7801

22.5
177.8279
22.6
181.9701
22.7
186.2087
22.8
190.5461
22.9
194.9845

23.0
199.5262
23.1
204.1738
23.2
208.9296
23.3
213.7962
23.4
218.7762

23.5
223.8721
23.6
229.0868
23.7
234.4229
23.8
239.8833
23.9
245.4709

24.0
251.1886
24.1
257.0396
24.2
263.0268
24.3
269.1535
24.4
275.4229

24.5
281.8383
24.6
288.4032
24.7
295.1209
24.8
301.9952
24.9
309.0295

25.0
316.2278
25.1
323.5937
25.2
331.1311
25.3
338.8442
25.4
346.7369

25.5
354.8134
25.6
363.0781
25.7
371.5352
25.8
380.1894
25.9
389.0451

26.0
398.1072
26.1
407.3803
26.2
416.8694
26.3
426.5795
26.4
436.5158

26.5
446.6836
26.6
457.0882
26.7
467.7351
26.8
478.6301
26.9
489.7788

27.0
501.1872
27.1
512.8614
27.2
524.8075
27.3
537.0318
27.4
549.5409

27.5
562.3413
27.6
575.4399
27.7
588.8437
27.8
602.5596
27.9
616.5950

28.0
630.9573
28.1
645.6542
28.2
660.6934
28.3
676.0830
28.4
691.8310

28.5
707.9458
28.6
724.4360
28.7
741.3102
28.8
758.5776
28.9
776.2471

29.0
794.3282
29.1
812.8305
29.2
831.7638
29.3
851.1380
29.4
870.9636

29.5
891.2509
29.6
912.0108
29.7
933.2543
29.8
954.9926
29.9
977.2372

30
1000.000
31
1258.925
32
1584.893
33
1995.262
34
2511.886

35
3162.278
36
3981.072
37
5011.872
38
6309.573
39
7943.282

40
10000.00
41
12589.25
42
15848.93
43
19952.62
44
25118.86

45
31622.78
46
39810.72
47
50118.72
48
63095.73
49
79432.82

Impressions from Egypt

It was very quite in my blog for more than 2 weeks.
Cause of the fact is that i spend a 2 week holiday in Egypt.
The first week, i did a Nile Cruise from Luxor to Aswan and back.
Second week was relaxing in Hurghada.
Here are some pictures without comments…
      
here’s the famous Aswan High Dam
    [...]

Added new Page - IOS and JunOS commands

Just now, i added a new sticky page to my blog.
It’s a small comparison between Cisco IOS and Juniper JunOS CLI commands.
See here…

SDH multiplex structure

 Synchronous Digital Hierarchy (SDH) is a CCITT standard for a hierarchy of optical transmission rates. Synchronous Optical Network (SONET) is an ANSI (American National Standards Institute) standard for North America, that is largely equivalent to SDH.
Both are widely spread technologies for very high speed transmission of voice and data signals across the numerous world-wide fiber-optic networks.
SDH and SONET are [...]

Administrative distance / Route preference

Juniper and Cisco use different values for the administrative distance of routes from specific Routing protocols.
To illustrate the differences, i will show two tables taken directly from the vendors homepages.
Cisco
(taken from Cisco website)

Route Source
Default Distance Values

Connected interface
0

Static route
1

Enhanced Interior Gateway Routing Protocol (EIGRP) summary route
5

External Border Gateway Protocol (BGP)
20

Internal EIGRP
90

IGRP
100

OSPF
110

Intermediate System-to-Intermediate System (IS-IS)
115

Routing Information Protocol (RIP)
120

Exterior [...]

Syslog facilities and priorities

syslog is the most common protcol for transmitting system messages over an IP network.
It is described at length in RFC 3164.
At the bottom of the post, you can find the meanings of syslog facility and severity (also known as priority)
Layout of a syslog message

Name of program
Facility
Priority/Severity
Message

Note: Not all parts are visible in the logfile(s), but [...]

BGP best path selection algorithm (Cisco specific)

(Most in this entry is taken directly from www.cisco.com. It’s just to have BGP decision process ready to hand…)
How the Best Path Algorithm Works
Just a BGP assigns the first valid path as the current best path. BGP then compares the best path with the next path in the list, until BGP reaches the end of the list [...]