Kita bisa mengubah configuration register untuk keperluan:
Memaksa system untuk masuk bootstrap monitor
Memilih sebuah boot source dan default boot filename
Enable atau men-disable fungsi break
Mengontrol alamat broadcast
Mengatur baud rate terminal console
Me-load software operating dari ROM
Booting dari TFTP server
Konfigurasi default pada Cisco router adalah 0×2102
Nomor bit pada configuration register
Prefix 0x pada alamat configuration register (0×2102) untuk menunjukkan bilangan yang digunakan adalah hexadecimal
Maksud dari Nomor Bit
Bit ke 6 digunakan untuk mengabaikan isi dari NVRAM
Boot field
Untuk boot ke mode ROM Monitor atur configuration register ke 0×2100, kemudian reboot router. Pada router akan muncul rommon>
Untuk booting ke mini-IOS images pada ROM (dikenal sebagai RXBOOT), atur configuration register ke 0×2101. Maka akan tampil router(boot)> Jika ini jenis router lama, atau akan muncul rommon 1> jika router berbasiskan RISC terbaru dengan sebuah “smart ROM” pengganti dari mini IOS.
Nilai dari 0×2102 sampai 0×210F untuk memberi tahu pada router untuk menggunakan perintah boot yang spesifik di NVRAM. Semua nilai dalam bentuk hexadecimal, skemanya adalah 0-9 dan A-F. (A=10, B=11, C=12, D=13, E=14, dan F=15). Sehingga kita mengatur configuration register sampai 210(15), atau 1111 dalam bentuk binary.
MENGUBAH CONFIGURATION REGISTER
Sebelum mengubah configuration register, maka perlu mengetahui nilai configuration register yang sudah ada. Pada router ketikkan perintah:
Router>enable
Router#show version
Cisco IOS Software, 1841 Software (C1841-ADVIPSERVICESK9-M), Version 12.4(15)T1, RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2007 by Cisco Systems, Inc.
Compiled Wed 18-Jul-07 04:52 by pt_team
ROM: System Bootstrap, Version 12.3(8r)T8, RELEASE SOFTWARE (fc1)
System returned to ROM by power-on
System image file is “flash:c1841-advipservicesk9-mz.124-15.T1.bin”
This product contains cryptographic features and is subject to United
States and local country laws governing import, export, transfer and
use. Delivery of Cisco cryptographic products does not imply
third-party authority to import, export, distribute or use encryption.
Importers, exporters, distributors and users are responsible for
compliance with U.S. and local country laws. By using this product you
agree to comply with applicable laws and regulations. If you are unable
to comply with U.S. and local laws, return this product immediately.
A summary of U.S. laws governing Cisco cryptographic products may be found at:
http://www.cisco.com/wwl/export/crypto/tool/stqrg.html
If you require further assistance please contact us by sending email to
export@cisco.com.
Cisco 1841 (revision 5.0) with 114688K/16384K bytes of memory.
Processor board ID FTX0947Z18E
M860 processor: part number 0, mask 49
2 FastEthernet/IEEE 802.3 interface(s)
191K bytes of NVRAM.
31360K bytes of ATA CompactFlash (Read/Write)
Configuration register is 0×2102
Untuk mengubah configuration register
Router#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#config-register 0×2101
Router(config)#^Z
%SYS-5-CONFIG_I: Configured from console by console
Router#show version
Cisco IOS Software, 1841 Software (C1841-ADVIPSERVICESK9-M), Version 12.4(15)T1, RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2007 by Cisco Systems, Inc.
Compiled Wed 18-Jul-07 04:52 by pt_team
ROM: System Bootstrap, Version 12.3(8r)T8, RELEASE SOFTWARE (fc1)
System returned to ROM by power-on
System image file is “flash:c1841-advipservicesk9-mz.124-15.T1.bin”
This product contains cryptographic features and is subject to United
States and local country laws governing import, export, transfer and
use. Delivery of Cisco cryptographic products does not imply
third-party authority to import, export, distribute or use encryption.
Importers, exporters, distributors and users are responsible for
compliance with U.S. and local country laws. By using this product you
agree to comply with applicable laws and regulations. If you are unable
to comply with U.S. and local laws, return this product immediately.
A summary of U.S. laws governing Cisco cryptographic products may be found at:
http://www.cisco.com/wwl/export/crypto/tool/stqrg.html
If you require further assistance please contact us by sending email to
export@cisco.com.
Cisco 1841 (revision 5.0) with 114688K/16384K bytes of memory.
Processor board ID FTX0947Z18E
M860 processor: part number 0, mask 49
2 FastEthernet/IEEE 802.3 interface(s)
191K bytes of NVRAM.
31360K bytes of ATA CompactFlash (Read/Write)
Configuration register is 0×2102 (will be 0×2101 at next reload)
PASSWORD RECOVERY
Bit ke 6 pada configuration register merupakan bit yang digunakan untuk memberi tahu router apakah harus menggunakan isi dari NVRAM, atau malah sebaliknya untuk mengabaikan isi dari NVRAM.
Nilai default dari configuration register adalah 0×2102, dimana bit ke tersebut dinyatakan off, jika nilai ini off maka router akan mencari dan me-loading konfigurasi yang disimpan pada NVRAM (startup-config). Untuk melakukan recovery password, kita perlu memberi nilai pada bit ke 6 tersebut, sehingga router akan mengabaikan startup-config yang terdapat pada NVRAM, sedangkan konfigurasi mengenai password tersendiri disimpan pada startup-config tersebut, jika startup-config diabaikan maka router tidak akan membaca password yang sudah ada.
Untuk melakukan recovery password pada router, hubungkan router pada program hyperterminal. Setelah itu matikanlah router, kemudian pada keyboard computer tekan Control+break, dan nyalakan lagi router. Router akan masuk ke ROM monitor, pada ROM monitor ketik perintah confreg 0×2142
rommon 1 > confreg 0×2142
rommon 2 > reset
Setelah direset maka router akan masuk ke configuration dialog, ketik no
System Bootstrap, Version 12.3(8r)T8, RELEASE SOFTWARE (fc1)
Cisco 1841 (revision 5.0) with 114688K/16384K bytes of memory.
Self decompressing the image :
########################################################################## [OK]
Restricted Rights Legend
Use, duplication, or disclosure by the Government is
subject to restrictions as set forth in subparagraph
(c) of the Commercial Computer Software - Restricted
Rights clause at FAR sec. 52.227-19 and subparagraph
(c) (1) (ii) of the Rights in Technical Data and Computer
Software clause at DFARS sec. 252.227-7013.
cisco Systems, Inc.
170 West Tasman Drive
San Jose, California 95134-1706
Cisco IOS Software, 1841 Software (C1841-ADVIPSERVICESK9-M), Version 12.4(15)T1, RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2007 by Cisco Systems, Inc.
Compiled Wed 18-Jul-07 04:52 by pt_team
Image text-base: 0×60080608, data-base: 0×6270CD50
This product contains cryptographic features and is subject to United
States and local country laws governing import, export, transfer and
use. Delivery of Cisco cryptographic products does not imply
third-party authority to import, export, distribute or use encryption.
Importers, exporters, distributors and users are responsible for
compliance with U.S. and local country laws. By using this product you
agree to comply with applicable laws and regulations. If you are unable
to comply with U.S. and local laws, return this product immediately.
A summary of U.S. laws governing Cisco cryptographic products may be found at:
http://www.cisco.com/wwl/export/crypto/tool/stqrg.html
If you require further assistance please contact us by sending email to
export@cisco.com.
Cisco 1841 (revision 5.0) with 114688K/16384K bytes of memory.
Processor board ID FTX0947Z18E
M860 processor: part number 0, mask 49
2 FastEthernet/IEEE 802.3 interface(s)
191K bytes of NVRAM.
31360K bytes of ATA CompactFlash (Read/Write)
Cisco IOS Software, 1841 Software (C1841-ADVIPSERVICESK9-M), Version 12.4(15)T1, RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2007 by Cisco Systems, Inc.
Compiled Wed 18-Jul-07 04:52 by pt_team
— System Configuration Dialog —
Continue with configuration dialog? [yes/no]:
Masuk ke privileges mode
Router>enable
Kemudian masuk ke Global Configuration Mode
Router#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Berikan password yang baru
Router(config)#enable secret candra
Kembalikan konfigurasi kenilai default
Router(config)#config-register 0×2102
Router(config)#^Z
%SYS-5-CONFIG_I: Configured from console by console
Simpan ke startup config
Router#copy run startup-config
Destination filename [startup-config]?
Building configuration…
[OK]
Reload router
Router#reload
Proceed with reload? [confirm]
%SYS-5-RELOAD: Reload requested by console. Reload Reason: Reload Command.
System Bootstrap, Version 12.3(8r)T8, RELEASE SOFTWARE (fc1)
Cisco 1841 (revision 5.0) with 114688K/16384K bytes of memory.
Self decompressing the image :
########################################################################## [OK]
Restricted Rights Legend
Use, duplication, or disclosure by the Government is
subject to restrictions as set forth in subparagraph
(c) of the Commercial Computer Software - Restricted
Rights clause at FAR sec. 52.227-19 and subparagraph
(c) (1) (ii) of the Rights in Technical Data and Computer
Software clause at DFARS sec. 252.227-7013.
cisco Systems, Inc.
170 West Tasman Drive
San Jose, California 95134-1706
Cisco IOS Software, 1841 Software (C1841-ADVIPSERVICESK9-M), Version 12.4(15)T1, RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2007 by Cisco Systems, Inc.
Compiled Wed 18-Jul-07 04:52 by pt_team
Image text-base: 0×60080608, data-base: 0×6270CD50
This product contains cryptographic features and is subject to United
States and local country laws governing import, export, transfer and
use. Delivery of Cisco cryptographic products does not imply
third-party authority to import, export, distribute or use encryption.
Importers, exporters, distributors and users are responsible for
compliance with U.S. and local country laws. By using this product you
agree to comply with applicable laws and regulations. If you are unable
to comply with U.S. and local laws, return this product immediately.
A summary of U.S. laws governing Cisco cryptographic products may be found at:
http://www.cisco.com/wwl/export/crypto/tool/stqrg.html
If you require further assistance please contact us by sending email to
export@cisco.com.
Cisco 1841 (revision 5.0) with 114688K/16384K bytes of memory.
Processor board ID FTX0947Z18E
M860 processor: part number 0, mask 49
2 FastEthernet/IEEE 802.3 interface(s)
191K bytes of NVRAM.
31360K bytes of ATA CompactFlash (Read/Write)
Cisco IOS Software, 1841 Software (C1841-ADVIPSERVICESK9-M), Version 12.4(15)T1, RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2007 by Cisco Systems, Inc.
Compiled Wed 18-Jul-07 04:52 by pt_team
%LINK-5-CHANGED: Interface Vlan1, changed state to up
%LINK-5-CHANGED: Interface FastEthernet0/0, changed state to up
%LINK-5-CHANGED: Interface FastEthernet0/1, changed state to up
%LINK-5-CHANGED: Interface FastEthernet0/0, changed state to administratively down
%LINK-5-CHANGED: Interface FastEthernet0/1, changed state to administratively down
%LINK-5-CHANGED: Interface Vlan1, changed state to administratively down
Press RETURN to get started!
Ketik enable dan masukkan password baru yang kita buat tadi
Router>enable
Password:
Router#
Jika interface pada router sudah ada konfigurasi mengenai IP address dan lain-lain, jangan lupa untuk masuk ke Interface mode karena seluruh interface kembali berada dalam kondisi down.
Sumber dari situs Candra.unsri.ac.id dengan judul Configuration Register
O, kayak gitu ya, waahh kuncinya ngerti hexadecimal ya, jadi nyambung nehhh, tengkiu banget
ReplyDeleteAss, Makasih infonya! jangan lupa menulis terus ces!
ReplyDelete