搜索

此内容没有您所选择的语言版本。

7.213. tcpdump

download PDF
Updated tcpdump packages that fix two bugs and add two enhancements are now available for Red Hat Enterprise Linux 6.
The tcpdump packages contain a command-line tool for monitoring network traffic. Tcpdump can capture and display the packet headers on a particular network interface or on all interfaces. Tcpdump can display all of the packet headers, or just the ones that match particular criteria.

Bug Fixes

BZ#972396
Previously, the tcpdump utility was treating the argument for the "-i" option as a number if it contained a numeric prefix and other characters, not as a string. Consequently, packet capturing was not started on a specified interface at all or could get started on a incorrect interface. With this update, the argument for "-i" is treated as a number only if it contains only numerals 0-9; otherwise, the argument is treated as a string. For example, interface names such as "192_1_2" are no longer treated as interface number 192, but as a string. As a result, tcpdump starts correctly on a specified interface even if the interface name contains a numeric prefix.
BZ#1130111
The tcpdump Cisco Discovery Protocol (CDP) dissector previously stopped parsing packet prematurely after encountering Type-Length-Value (TLV) field which had the length of 0 and no data associated with it. Consequently, some CDP packets were not completely dissected. A patch which alters code deciding when to stop parsing the packet has been applied to fix this bug. Now, zero length data TLVs are allowed, and CDP packets containing such TLVs are parsed correctly.

Enhancements

BZ#1045601
The kernel, glibc, and libpcap utilities now provide APIs to obtain nanosecond resolutions timestamps. The user can thus query which timestamp sources are available ("-J"), set a specific timestamp source ("-j"), and request timestamps with a specified resolution ("--time-stamp-precision").
BZ#1099701
This update adds the new "-P" command-line argument for capturing packets in certain direction, which can ease debugging networking-related problems.
Users of tcpdump are advised to upgrade to these updated packages, which fix these bugs and add these enhancements.
Red Hat logoGithubRedditYoutubeTwitter

学习

尝试、购买和销售

社区

关于红帽文档

通过我们的产品和服务,以及可以信赖的内容,帮助红帽用户创新并实现他们的目标。

让开源更具包容性

红帽致力于替换我们的代码、文档和 Web 属性中存在问题的语言。欲了解更多详情,请参阅红帽博客.

關於紅帽

我们提供强化的解决方案,使企业能够更轻松地跨平台和环境(从核心数据中心到网络边缘)工作。

© 2024 Red Hat, Inc.