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In "Requirement for internet hosts", a respected authority responsible for the standarization of the ICMP, TCP, IP and other protocols, the IETF, specifies that hosts should respond to ICMP Queries. So not only is the practice safe, but it's considered mandatory for compliancy with their standards:

Every host MUST implement an ICMP Echo server function that receives Echo Requests and sends corresponding Echo Replies. A host SHOULD also implement an application-layer interface for sending an Echo Request and receiving an Echo Reply, for diagnostic purposes.

In standard IETF language, MUST means that "the item is an absolute requirement of the specification." While SHOULD means that that there "may exist valid reasons in particular circumstances to ignore this item, but the full implications should be understood"

This means that a server must respond to an ICMP Echo Query, but may not provide a user interface for them.

The document refers to an extensive debate that took place before the date of the redaction 1989:

"This neutral provision results from a passionate debate between those who feel that ICMP Echo to a broadcast address provides a valuable diagnostic capability and those who feel that misuse of this feature can too easily create packet storms."

Even after more recent (2010) discussions on theoretical attacks through ICMP on RFC 5927, the IETF still didn't downgrade ICMP ECHO Responses from a MUST to a SHOULD. The target of this RFC are vendors and implementers of ICMP and TCP, not consumers. The worst-case scenarios described are degradation of service.

In short, ICMP is safe. Disabling is not recommended.

If you respect the shoulders of the giants you stand on, you will respect their decision and avoid deviating from convention.

In "Requirement for internet hosts", a respected authority responsible for the standarization of the ICMP, TCP, IP and other protocols, the IETF, specifies that hosts should respond to ICMP Queries. So not only is the practice safe, but it's considered mandatory for compliancy with their standards:

Every host MUST implement an ICMP Echo server function that receives Echo Requests and sends corresponding Echo Replies. A host SHOULD also implement an application-layer interface for sending an Echo Request and receiving an Echo Reply, for diagnostic purposes.

In standard IETF language, MUST means that "the item is an absolute requirement of the specification." While SHOULD means that that there "may exist valid reasons in particular circumstances to ignore this item, but the full implications should be understood"

This means that a server must respond to an ICMP Echo Query, but may not provide a user interface for them.

The document refers to an extensive debate that took place before the date of the redaction 1989:

"This neutral provision results from a passionate debate between those who feel that ICMP Echo to a broadcast address provides a valuable diagnostic capability and those who feel that misuse of this feature can too easily create packet storms."

Even after more recent (2010) discussions on theoretical attacks through ICMP on RFC 5927, the IETF still didn't downgrade ICMP ECHO Responses from a MUST to a SHOULD. The target of this RFC are vendors and implementers of ICMP and TCP, not consumers. The worst-case scenarios described are degradation of service.

In short, ICMP is safe. Disabling is not recommended.

If you respect the shoulders of the giants you stand on, you will respect their decision and avoid deviating from convention.

In "Requirement for internet hosts", a respected authority responsible for the standarization of the ICMP, TCP, IP and other protocols, the IETF, specifies that hosts should respond to ICMP Queries. So not only is the practice safe, but it's considered mandatory for compliancy with their standards:

Every host MUST implement an ICMP Echo server function that receives Echo Requests and sends corresponding Echo Replies. A host SHOULD also implement an application-layer interface for sending an Echo Request and receiving an Echo Reply, for diagnostic purposes.

In standard IETF language, MUST means that "the item is an absolute requirement of the specification." While SHOULD means that that there "may exist valid reasons in particular circumstances to ignore this item, but the full implications should be understood"

This means that a server must respond to an ICMP Echo Query, but may not provide a user interface for them.

The document refers to an extensive debate that took place before the date of the redaction 1989:

"This neutral provision results from a passionate debate between those who feel that ICMP Echo to a broadcast address provides a valuable diagnostic capability and those who feel that misuse of this feature can too easily create packet storms."

Even after more recent (2010) discussions on theoretical attacks through ICMP on RFC 5927, the IETF still didn't downgrade ICMP ECHO Responses from a MUST to a SHOULD. The target of this RFC are vendors and implementers of ICMP and TCP, not consumers. The worst case scenarios described are degradation of service.

In short, ICMP is safe. Disabling is not recommended.

If you respect the shoulders of the giants you stand on, you will respect their decision and avoid deviating from convention.

In "Requirement for internet hosts", a respected authority responsible for the standarization of the ICMP, TCP, IP and other protocols, the IETF, specifies that hosts should respond to ICMP Queries. So not only is the practice safe, but it's considered mandatory for compliancy with their standards:

Every host MUST implement an ICMP Echo server function that receives Echo Requests and sends corresponding Echo Replies. A host SHOULD also implement an application-layer interface for sending an Echo Request and receiving an Echo Reply, for diagnostic purposes.

In standard IETF language, MUST means that "the item is an absolute requirement of the specification." While SHOULD means that that there "may exist valid reasons in particular circumstances to ignore this item, but the full implications should be understood"

This means that a server must respond to an ICMP Echo Query, but may not provide a user interface for them.

The document refers to an extensive debate that took place before the date of the redaction 1989:

"This neutral provision results from a passionate debate between those who feel that ICMP Echo to a broadcast address provides a valuable diagnostic capability and those who feel that misuse of this feature can too easily create packet storms."

Even after more recent (2010) discussions on theoretical attacks through ICMP on RFC 5927, the IETF still didn't downgrade ICMP ECHO Responses from a MUST to a SHOULD. The target of this RFC are vendors and implementers of ICMP and TCP, not consumers. The worst-case scenarios described are degradation of service.

In short, ICMP is safe. Disabling is not recommended.

If you respect the shoulders of the giants you stand on, you will respect their decision and avoid deviating from convention.

According to Internet Engineering Task Force's "Requirement for internet hosts", internet compliant hosts MUST respond to ICMP Queries. So not only is the practice safe, but it's considered mandatory in the open web:

Every host MUST implement an ICMP Echo server function that receives Echo Requests and sends corresponding Echo Replies. A host SHOULD also implement an application-layer interface for sending an Echo Request and receiving an Echo Reply, for diagnostic purposes.

In standard IETF language, MUST means that "the item is an absolute requirement of the specification." While SHOULD means that that there "may exist valid reasons in particular circumstances to ignore this item, but the full implications should be understood"

This means that a server must respond to an ICMP Echo Query, but may not provide a user interface for them.

The document refers to an extensive debate that took place before the date of the redaction 1989:

"This neutral provision results from a passionate debate between those who feel that ICMP Echo to a broadcast address provides a valuable diagnostic capability and those who feel that misuse of this feature can too easily create packet storms."

Even after more recent (2010) discussions on theoretical attacks through ICMP on RFC 5927, the IETF still didn't downgrade ICMP ECHO Responses from a MUST to a SHOULD. The target of this RFC are vendors and implementers of ICMP and TCP, not consumers. The worst case scenarios described are degradation of service.

In short, ICMP is safe. Disabling is not recommended.

If you respect the shoulders of the giants you stand on, you will respect their decision and avoid deviating from convention.

In "Requirement for internet hosts", a respected authority responsible for the standarization of the ICMP, TCP, IP and other protocols, the IETF, specifies that hosts should respond to ICMP Queries. So not only is the practice safe, but it's considered mandatory for compliancy with their standards:

Every host MUST implement an ICMP Echo server function that receives Echo Requests and sends corresponding Echo Replies. A host SHOULD also implement an application-layer interface for sending an Echo Request and receiving an Echo Reply, for diagnostic purposes.

In standard IETF language, MUST means that "the item is an absolute requirement of the specification." While SHOULD means that that there "may exist valid reasons in particular circumstances to ignore this item, but the full implications should be understood"

This means that a server must respond to an ICMP Echo Query, but may not provide a user interface for them.

The document refers to an extensive debate that took place before the date of the redaction 1989:

"This neutral provision results from a passionate debate between those who feel that ICMP Echo to a broadcast address provides a valuable diagnostic capability and those who feel that misuse of this feature can too easily create packet storms."

Even after more recent (2010) discussions on theoretical attacks through ICMP on RFC 5927, the IETF still didn't downgrade ICMP ECHO Responses from a MUST to a SHOULD. The target of this RFC are vendors and implementers of ICMP and TCP, not consumers. The worst case scenarios described are degradation of service.

In short, ICMP is safe. Disabling is not recommended.

If you respect the shoulders of the giants you stand on, you will respect their decision and avoid deviating from convention.