diff options
Diffstat (limited to 'passt.1')
| -rw-r--r-- | passt.1 | 39 |
1 files changed, 27 insertions, 12 deletions
@@ -156,26 +156,35 @@ By default, the advertised MTU is 65520 bytes, that is, the maximum 802.3 MTU minus the length of a 802.3 header, rounded to 32 bits (IPv4 words). .TP -.BR \-a ", " \-\-address " " \fIaddr +.BR \-a ", " \-\-address " " \fIaddr\fR[/\fIprefix_len\fR] Assign IPv4 \fIaddr\fR via DHCP (\fByiaddr\fR), or \fIaddr\fR via DHCPv6 (option 5) and an \fIaddr\fR-based prefix via NDP Router Advertisement (option type 3) for an IPv6 \fIaddr\fR. +An optional /\fIprefix_len\fR (0-32 for IPv4, 0-128 for IPv6) can be +appended in CIDR notation (e.g. 192.0.2.1/24). This is an alternative to +using the \fB-n\fR, \fB--netmask\fR option. Mixing CIDR notation with +\fB-n\fR results in an error. +If a prefix length is assigned to an IPv6 address using this method, it will +in the current code version be overridden by the default value of 64. This option can be specified zero (for defaults) to two times (once for IPv4, once for IPv6). By default, assigned IPv4 and IPv6 addresses are taken from the host interfaces with the first default route, if any, for the corresponding IP version. If no default routes are available and there is any interface with any route for a given IP version, the first of these interfaces will be chosen instead. If no -such interface exists, the link-local address 169.254.2.1 is assigned for IPv4, -and no additional address will be assigned for IPv6. +such interface exists for a given IP version, the link-local address 169.254.2.1 +is assigned for IPv4, and no additional address will be assigned for IPv6. .TP .BR \-n ", " \-\-netmask " " \fImask Assign IPv4 netmask \fImask\fR, expressed as dot-decimal or number of bits, via -DHCP (option 1). -By default, the netmask associated to the host address matching the assigned one -is used. If there's no matching address on the host, the netmask is determined -according to the CIDR block of the assigned address (RFC 4632). +DHCP (option 1). Alternatively, the prefix length can be specified using CIDR +notation with the \fB-a\fR, \fB--address\fR option (e.g. \fB-a\fR 192.0.2.1/24). +Mixing \fB-n\fR with CIDR notation results in an error. +If no address is indicated, the netmask associated with the adopted host address, +if any, is used. If an address is indicated, but without a prefix length, the +netmask is determined based on the corresponding network class. In all other +cases, the netmask is determined by using the indicated prefix length. .TP .BR \-M ", " \-\-mac-addr " " \fIaddr @@ -194,9 +203,9 @@ first default route, if any, for the corresponding IP version. If the default route is a multipath one, the gateway is the first nexthop router returned by the kernel which has the highest weight in the set of paths. If no default routes are available and there is just one interface with any route, that -interface will be chosen instead. If no such interface exists, the link-local -address 169.254.2.2 is used for IPv4, and the link-local address fe80::1 is used -for IPv6. +interface will be chosen instead. If no such interface exists for a given IP +version, the link-local address 169.254.2.2 is used for IPv4, and the link-local +address fe80::1 is used for IPv6. Note: these addresses are also used as source address for packets directed to the guest or to the target namespace having a loopback or local source address, @@ -755,6 +764,11 @@ Default is to let the tap driver build a pseudorandom hardware address. Disable the bypass path for inbound, local traffic. See the section \fBHandling of local traffic in pasta\fR in the \fBNOTES\fR for more details. +.TP +.BR \-\-splice-only +Do not create a tap device in the namespace. In this mode, \fIpasta\fR only +forwards loopback traffic between namespaces. + .SH EXAMPLES .SS \fBpasta @@ -1117,8 +1131,9 @@ throughput of TCP connections. .SS Local mode for disconnected setups If \fBpasst\fR and \fBpasta\fR fail to find a host interface with a configured -address, other than loopback addresses, they will, obviously, not attempt to -source addresses or routes from the host. +address for a given IP version, other than loopback addresses, they will, +obviously, not attempt to source addresses or routes from the host, for that +IP version. In this case, unless configured otherwise, they will assign the IPv4 link-local address 169.254.2.1 to the guest or target namespace, and no IPv6 address. The |