Summary: | multiple ICMP echo requests reported when ping broadcast | ||
---|---|---|---|
Product: | Base System | Reporter: | Hannes Mehnert <hannes> |
Component: | kern | Assignee: | George V. Neville-Neil <gnn> |
Status: | New --- | ||
Severity: | Affects Many People | CC: | ae, gnn, pstef |
Priority: | --- | ||
Version: | CURRENT | ||
Hardware: | Any | ||
OS: | Any |
Description
Hannes Mehnert
2017-09-11 20:56:38 UTC
You see two copies of the broadcast packet, because wlan0 has IFF_SIMPLEX flag and ether_output() does if_simloop() for broadcast packets for those interfaces. Interfaces with IFF_SIMPLEX flag can not receive their own broadcast packets, and the kernel emulates this behavior. So you can "receive" you own broadcast on the link. You can use tcpdump with -Q in|out flag to check, that one packet is outbound, and other is inbound. George, do you think this doesn't work as intended? |