AI, ML, Development + Cisco Learning Blog Learning about Machine Learning, Artificial Intelligence, related devlopment topics and formerly Routing and Switching, Datacenter, Security and other topics, CCIE #23664, Frank Wagner

30. November 2006

What’s the difference between „ntp server“ and „ntp peer“?

Filed under: IP and IOS Features — ocsic @ 10:56

There are three possible relationships that ntp can establish.

  • client-server
  • peer-peer
  • sending broadcasts

With „ntp server“ only the client can get the time from the server.

With „ntp peer“ there is a peering relationship established and both can get the time from each other, regarding to the lower stratum.

As for example, i have router A, B and C. B is configured as a clients of A with „ntp server A“.

So A will provide the time for B. B will only get the time from A.

C is configured with „ntp peer B“. So C and B will share time information and can syncronize to each other, depending on which one has a better stratum.

All routers configured with the peer command can be „bound“ together inside a full mesh, where then every router is participating in the best time sync.

14. November 2006

LSA types in different areas

Filed under: OSPF — ocsic @ 14:08
  • Backbone Area: 1,2,3,4,5
  • Non-Backbone Area, non-stub: 1,2,3,5,
  • Stub: 1,2,3,4
  • Totally stubby: 1,2 (except also for type-3 default route)
  • Not-so-stubby: 1,2,3,4,7
  • stub: area number stub, 1,2,3,4
  • totally stubby: area number stub no-summary,1,2 def 3
  • no-so-stubby: area number nssa,1,2,3,4,7
  • not-so-totally-stubby: area 1 nssa no-summary ,1,2,def 3, 7

Source: TCP/IP Vol1, page 484

7. November 2006

IP Address space

Filed under: Allgemein — ocsic @ 06:32
Class Address Range Supports
Class A 1.0.0.1 to 126.255.255.254 Supports 16 million hosts on each of 127 networks.
Class B 128.1.0.1 to 191.255.255.254 Supports 65,000 hosts on each of 16,000 networks.
Class C 192.0.1.1 to 223.255.254.254 Supports 254 hosts on each of 2 million networks.
Class D 224.0.0.0 to 239.255.255.255 Reserved for multicast groups.
Class E 240.0.0.0 to 254.255.255.254 Reserved.

Source:

http://www.computerhope.com/jargon/i/ip.htm

6. November 2006

Some kind of revolution going on …

Filed under: Allgemein — ocsic @ 18:01

CCIE without this bunch of hardware….

Dynamips

http://hacki.at/7200emu/viewtopic.php?t=121&postdays=0&postorder=asc&start=0

4. November 2006

Newest spam…

Filed under: Allgemein — ocsic @ 18:09

I don’t know really what that makes, but there is a new funny kind of spam.

It’s just about nothing.

The mailcontent is just:

——————————————–

From:  SamxxxHxxxxxxx@boxxxxxx.com

To:  8209340922@324230942.com

Hi john.
How are you ? Call me.
--------------------------------------------


Who is John? Do you know that? I don't know. May be someone has a hint.

	


	







3. November 2006



	 
3640 crashing and booting in a loop

	
Filed under: Lab —  ocsic @ 11:06 


	

		
It’s probably these day’s you should not touch any electronic system.


Just does not having it that often, but it happens, when i did not think about it or when i expect it the least. It tried to enter an ipv6 access list:

Rack1R3(config)#ipv6 prefix-list PRE_IPV6 ?

deny         Specify packets to reject

description  Prefix-list specific description

permit       Specify packets to forward

seq          sequence number of an entry


Rack1R3(config)#ipv6 prefix-list PRE_IPV6 deny FEC0:145:1:34::/64


%ALIGN-1-FATAL: Corrupted program counter 14:27:14 UTC Mon Jan 2 2006

pc=0x0 , ra=0x62139A40 , sp=0x652884B0


%ALIGN-1-FATAL: Corrupted program counter 14:27:14 UTC Mon Jan 2 2006

pc=0x0 , ra=0x62139A40 , sp=0x652884B0


14:27:14 UTC Mon Jan 2 2006: TLB (load or instruction fetch) exception, CPU signal 10, PC = 0x0


——————————————————————–

Possible software fault. Upon reccurence,  please collect

crashinfo, „show tech“ and contact Cisco Technical Support.

——————————————————————–


-Traceback=

$0 : 00000000, AT : 644D0000, v0 : 00000000, v1 : 00000000

a0 : 65A086AC, a1 : 00000000, a2 : 6597ED7C, a3 : 00000000

t0 : 00000018, t1 : 3401FF01, t2 : 3401E100, t3 : FFFF00FF

t4 : 60636260, t5 : 6493FAD8, t6 : 6493FAD4, t7 : 6493FAD0

s0 : 6597ED7C, s1 : 65A086AC, s2 : 6597F088, s3 : 00000002

s4 : 6488A5F0, s5 : 64890000, s6 : 6488A810, s7 : 659B7CFC

t8 : 65946D14, t9 : 00000000, k0 : 649C387C, k1 : 60603E80

gp : 644D4AC0, sp : 652884B0, s8 : 64780000, ra : 62139A40

EPC  : 00000000, ErrorEPC : BFC04560, SREG     : 3401FF03

MDLO : 00000000, MDHI     : 00000002, BadVaddr : 00000000

Cause 00000008 (Code 0x2): TLB (load or instruction fetch) exception


No fault history 0xFFFFFFFF. Need 11.1 (2) or higher ROM


Writing crashinfo to flash:crashinfo_20060102-142714


14:27:14 UTC Mon Jan 2 2006: TLB (load or instruction fetch) exception, CPU signal 10, PC = 0x0


——————————————————————–

Possible software fault. Upon reccurence,  please collect

crashinfo, „show tech“ and contact Cisco Technical Support.

——————————————————————–


-Traceback=

$0 : 00000000, AT : 644D0000, v0 : 00000000, v1 : 00000000

a0 : 65A086AC, a1 : 00000000, a2 : 6597ED7C, a3 : 00000000

t0 : 00000018, t1 : 3401FF01, t2 : 3401E100, t3 : FFFF00FF

t4 : 60636260, t5 : 6493FAD8, t6 : 6493FAD4, t7 : 6493FAD0

s0 : 6597ED7C, s1 : 65A086AC, s2 : 6597F088, s3 : 00000002

s4 : 6488A5F0, s5 : 64890000, s6 : 6488A810, s7 : 659B7CFC

t8 : 65946D14, t9 : 00000000, k0 : 649C387C, k1 : 60603E80

gp : 644D4AC0, sp : 652884B0, s8 : 64780000, ra : 62139A40

EPC  : 00000000, ErrorEPC : BFC04560, SREG     : 3401FF03

MDLO : 00000000, MDHI     : 00000002, BadVaddr : 00000000

Cause 00000008 (Code 0x2): TLB (load or instruction fetch) exception


-Traceback=


=== Flushing messages (14:27:14 UTC Mon Jan 2 2006) ===


Queued messages

*** System received a Bus Error exception ***

signal= 0xa, code= 0x8, context= 0x647b46d4

PC = 0x6063787c, Cause = 0x420, Status Reg = 0x34018002


System Bootstrap, Version 11.1(20)AA2, EARLY DEPLOYMENT RELEASE SOFTWARE (fc1)

Copyright (c) 1999 by cisco Systems, Inc.

C3600 processor with 131072 Kbytes of main memory

Main memory is configured to 64 bit mode with parity disabled


Well, and it’s repeating. It’s in a boot loop.


I had to set config register 0x2142 and then load the IOS without configuration:


…


*Mar  1 00:00:21.495: %LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel34, changed state to down

*Mar  1 00:00:21.499: %LINEPROTO-5-UPDOWN: Line protocol on Interface Loopback0, changed state to up

*Mar  1 00:00:21.699: %LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel35, changed state to down

*** System received a Bus Error exception ***

signal= 0xa, code= 0x8, context= 0x647b46d4

PC = 0x6063787c, Cause = 0x420, Status Reg = 0x34018002


System Bootstrap, Version 11.1(20)AA2, EARLY DEPLOYMENT RELEASE SOFTWARE (fc1)

Copyright (c) 1999 by cisco Systems, Inc.

C3600 processor with 131072 Kbytes of main memory

Main memory is configured to 64 bit mode with parity disabled


telnet> send brk

PC = 0xbfc0a024, Cause = 0x2000, Status Reg = 0x3041f003


monitor: command „boot“ aborted due to user interrupt

rommon 1 > confreg 0x2142


You must reset or power cycle for new config to take effect

rommon 2 > reset


Now i can change the config.


Source:


http://www.cisco.com/en/US/products/sw/iosswrel/ps1831/products_tech_note09186a00800cdd51.shtml#more

	


	
















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