Cisco Learning Blog

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.

• 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

Source:

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

CCIE without this bunch of hardware….

Dynamips

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

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.

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=0×0 , ra=0×62139A40 , sp=0×652884B0

%ALIGN-1-FATAL: Corrupted program counter 14:27:14 UTC Mon Jan 2 2006
pc=0×0 , ra=0×62139A40 , sp=0×652884B0

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

——————————————————————–
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 0×2): 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 = 0×0

——————————————————————–
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 0×2): 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= 0×8, context= 0×647b46d4
PC = 0×6063787c, Cause = 0×420, Status Reg = 0×34018002

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 0×2142 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= 0×8, context= 0×647b46d4
PC = 0×6063787c, Cause = 0×420, Status Reg = 0×34018002

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 = 0×2000, Status Reg = 0×3041f003

monitor: command “boot” aborted due to user interrupt
rommon 1 > confreg 0×2142

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