From: austin.alao@xxxxxx
Date: Tue Aug 07 2001 - 07:22:06 GMT-3
I think this is an easy one.
It is not the address that maters per se; but the address mask pair.
With BGP's support of CIDR, while 192.168.0.0 255.255.0.0 may be private,
192.168.x.x /16 le 15 is not. So addresses such as 192.168.x.x /8 is a valid
routable address.
Therefore, you need to analyse in terms of classless routing to make sense
of the trace below.
With protocols such as BGP an address means nothing unless you have the
prefix length as class-based routing is no longer the norm.
Hope this helps,
Austin Alao,
01442 431 247 / 07764 356 424
"The significant problems we face cannot be solved at the same level of
thinking we were at when we created them."
-Albert Einstein.
-----Original Message-----
From: Karelis, Pete (2507) [mailto:Pete.Karelis@esavio.com]
Sent: 06 August 2001 07:01
To: 'Craig Hammer'; ccielab@groupstudy.com
Subject: RE: Routing
RFC 1918 states the following IP address ranges as private:
10.0.0.0 mask 255.0.0.0
172.16.0.0 mask 255.240.0.0
192.168.0.0 mask 255.255.0.0
So this includes:
the whole 10 Class A
172.16.0.0 through 172.31.0.0 Class B's (16 Class B's)
192.168.0.0 through 192.168.255.0 Class C's (256 Class C's)
-Pete Karelis
-----Original Message-----
From: Craig Hammer [mailto:Craig.Hammer@Parago.Com]
Sent: Monday, August 06, 2001 9:40 AM
To: ccielab@groupstudy.com
Subject: RE: Routing
Last time I checked, 172.20.x.x is a publicly routable address.
-----Original Message-----
From: Leonard @ iname.com [mailto:Leonard_Ong@iname.com]
Sent: Monday, August 06, 2001 8:20 AM
To: ccielab@groupstudy.com
Subject: Routing
Hello Guys,
I found some traceroute that really bothers me and I don't know the
answer. Would you kindly explain it to me ?
traceroute from access.net.id to 202.156.227.140
1 202.180.0.4 (202.180.0.4) 2.502 ms 2.017 ms 1.641 ms
2 202.155.7.25 (202.155.7.25) 91.019 ms 28.084 ms 30.019 ms
3 202.155.7.85 (202.155.7.85) 55.545 ms 59.557 ms 23.195 ms
4 202.155.7.246 (202.155.7.246) 62.904 ms 25.812 ms 68.068 ms
5 500.POS1-2.IG2.SAC1.ALTER.NET (157.130.193.221) 210.419 ms 210.405
ms 305.777 ms
6 0.so-0-0-0.XR2.SAC1.ALTER.NET (152.63.54.118) 240.747 ms 208.259
ms 216.579 ms
7 0.so-0-0-0.TR2.SAC1.ALTER.NET (152.63.3.197) 247.044 ms 217.252
ms 253.461 ms
8 127.ATM5-0.IR2.SAC1.ALTER.NET (152.63.11.113) 209.069 ms 226.315
ms 208.555 ms
9 POS3-0.IR2.SAC2.ALTER.NET (137.39.31.209) 204.193 ms 209.688
ms 265.266 ms
10 210.80.49.230 (210.80.49.230) 441.732 ms
335.ATM5-0-0.TR2.SIN1.ALTER.NET (210.80.51.142) 514.855 ms
435.ATM5-0-0.TR2.SIN1.ALTER.NET (210.80.51.134) 526.292 ms
11 POS1-0-0.XR2.SIN1.Alter.Net (210.80.48.62) 456.046 ms 473.853
ms 472.113 ms
12 312.ATM3-0-0.GW2.SIN1.Alter.Net (210.80.2.202) 451.268 ms 458.89
ms 434.287 ms
13 scv-gw-33.customer.alter.net (202.95.97.14) 544.822 ms 450.079
ms 460.404 ms
14 172.20.6.11 (172.20.6.11) 466.566 ms 516.396 ms 464.313 ms
15 172.20.2.15 (172.20.2.15) 458.438 ms 464.12 ms 446.679 ms
16 172.20.15.2 (172.20.15.2) 465.278 ms 476.811 ms 570.675 ms
17 mcns140.docsis227.singa.pore.net (202.156.227.140) 493.695 ms 494.196
ms 525.214 ms
If you check the entry 14-16 it is private address which is supposedly not
routeable... and it goes at entry 17 to end-host of this ISP/cable... which
is routeable address... Any idea ?
Thanks
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