HP AdvanceStack Internet Router manual Virtual Configuration Register Settings

Maintenance

Troubleshooting

Virtual Configuration Register Settings

Virtual Configuration Register Settings

The router has a 16-bit virtual configuration register, which is written into NVRAM. You might want to change the virtual configuration register settings for the following reasons:

■Set and display the configuration register value

■Force the system into the ROM monitor or boot ROM

■Select a boot source and default boot filename

■Enable or disable the Break function

■Control broadcast addresses

■Set the console terminal baud rate

■Recover a lost password (ignore the configuration file in NVRAM)

■Enable TFTP server boot

Table 4-3 lists the meaning of each of the virtual configuration memory bits, and defines the boot field names.

C A U T I O N		To avoid confusion and possibly halting the router, remember that valid
		configuration register settings might be combinations of settings and not just
		the individual settings listed in table 4-3. For example, the factory default value
		of 0x2102 is a combination of settings.
		Table 4-3.	Virtual Configuration Register Bit Meanings
		Bit No.a	Hexadecimal	Meaning
		00–03	0x0000–0x000F	Boot field
	06		0x0040	Causes system software to ignore the contents of
				NVRAM (startup-config)
	07		0x0080	OEM bit is enabled
	08		0x0100	Break is disabled
	10		0x0400	IP broadcast with all zeros
		11–12	0x0800–0x1000	Console line speed
	13		0x2000	Load the boot ROM software if a Flash boot fails five
				times
	14		0x4000	IP broadcasts do not have network numbers
	15		0x8000	Enable diagnostic messages and ignore the contents
				of NVRAM

a.The factory default value for the configuration register is 0x2102. This value is a combination of the following: bit 13 = 0x2000, bit 8 = 0x0100, and bits 00 to 03 = 0x0002.

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