Bug 190425
Summary: | /etc/ethers file format | ||
---|---|---|---|
Product: | Red Hat Enterprise Linux 4 | Reporter: | Peter Riley <peter.riley> |
Component: | net-tools | Assignee: | Radek Vokál <rvokal> |
Status: | CLOSED RAWHIDE | QA Contact: | Ben Levenson <benl> |
Severity: | low | Docs Contact: | |
Priority: | medium | ||
Version: | 4.0 | ||
Target Milestone: | --- | ||
Target Release: | --- | ||
Hardware: | All | ||
OS: | Linux | ||
Whiteboard: | |||
Fixed In Version: | 1.60-69 | Doc Type: | Bug Fix |
Doc Text: | Story Points: | --- | |
Clone Of: | Environment: | ||
Last Closed: | 2006-05-02 12:46:38 UTC | Type: | --- |
Regression: | --- | Mount Type: | --- |
Documentation: | --- | CRM: | |
Verified Versions: | Category: | --- | |
oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
Cloudforms Team: | --- | Target Upstream Version: | |
Embargoed: |
Description
Peter Riley
2006-05-02 08:11:41 UTC
Oops.
> Running the "arp -f" command definitely chokes when
> the /etc/ethers file is in the format that its own
> "man 5 ethers" page describes.
Please ignore this part; "arp -f" works well with either
format of the /etc/ethers file. Indeed, it even works when
lines of *both* formats are present together in the same
file.
I became confused because I had unwittingly introduced
extraneous whitespace on several lines in the file while
swapping columns; and unfortunately, arp complains about
extra whitespace on an otherwise blank line. For example,
echo " " >> /etc/ethers; arp -f
will produce this error
arp: format error on line %u of etherfile /etc/ethers !
I had mistakenly thought it errored because the columns
had been swapped.
----
Also, while looking through net-tools-1.60-37.EL4.6.src.rpm
I came across this in arp.c:
380: /* Process an EtherFile */
381: static int arp_file(char *name)
382: {
...
408: if (strchr (args[0], ':') != NULL) {
409: /* We have a correct ethers file, switch hw adress and hostname
410: for arp */
411: char *cp;
412: cp = args[1];
413: args[1] = args[0];
414: args[0] = cp;
415: }
If the author of arp says that the "hwaddr ipaddr" order is correct,
the arp manpage must be wrong/unclear.
This bug could be closed, I think, if the ordering in the arp manpage
was switched here:
148: The format of the file is simple; it
149: only contains ASCII text lines with a hostname, and a hardware
150: address separated by whitespace. Additionally the
-PWR
I've changed the man page for rawhide, not a big issue for RHEL I think. You're right that both formats are more or less correct (eg. they are accepted by arp) |